0

I had Ubuntu 18.04 LTS installed. Then I dual booted it with Windows 7. After using boot repair from live USB, it showed

boot successfully repaired

But I still I can't see the GRUB screen and it directly boots Windows 7.

Trimmed boot info output - the full report is pasted here

============================= Boot Info Summary: ===============================

 => Syslinux MBR (5.00 and higher) is installed in the MBR of /dev/sda.
 => No known boot loader is installed in the MBR of /dev/sdb.

sda1: __________________________________________________________________________

    File system:       Extended Partition
    Boot sector type:  -
    Boot sector info: 

sda5: __________________________________________________________________________

    File system:       swap
    Boot sector type:  -
    Boot sector info: 

sda2: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info: 
    Operating System:  
    Boot files:        

sda3: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 7/2008: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        /bootmgr /Boot/BCD

sda4: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Windows 7/2008: NTFS
    Boot sector info:  No errors found in the Boot Parameter Block.
    Operating System:  
    Boot files:        /Windows/System32/winload.exe

sdb1: __________________________________________________________________________

    File system:       iso9660
    Boot sector type:  Unknown
    Boot sector info: 
    Mounting failed:   mount: /mnt/BootInfo/sdb1: /dev/sdb1 already mounted or mount point busy.

sdb2: __________________________________________________________________________

    File system:       vfat
    Boot sector type:  FAT16
    Boot sector info:  According to the info in the boot sector, sdb2 starts 
                       at sector 0. But according to the info from fdisk, 
                       sdb2 starts at sector 3737268. According to the info 
                       in the boot sector, sdb2 has 0 sectors.
    Mounting failed:   mount: /mnt/BootInfo/sdb1: /dev/sdb1 already mounted or mount point busy.
mount: /mnt/BootInfo/sdb2: /dev/sdb2 already mounted or mount point busy.

============================ Drive/Partition Info: =============================

Drive: sda _____________________________________________________________________
Disk /dev/sda: 465.8 GiB, 500107862016 bytes, 976773168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sda1               2,046   199,313,407   199,311,362   5 Extended
/dev/sda5         183,689,216   199,313,407    15,624,192  82 Linux swap / Solaris
/dev/sda2         296,970,240   492,281,855   195,311,616  83 Linux
/dev/sda3    *    492,281,856   492,486,655       204,800   7 NTFS / exFAT / HPFS
/dev/sda4         492,486,656   697,081,855   204,595,200   7 NTFS / exFAT / HPFS


Drive: sdb _____________________________________________________________________
Disk /dev/sdb: 7.5 GiB, 8004304896 bytes, 15633408 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sdb1    *              0     3,815,135     3,815,136   0 Empty
/dev/sdb2           3,737,268     3,741,939         4,672  ef EFI (FAT-12/16/32)

/dev/sdb1 overlaps with /dev/sdb2

GUID Partition Table detected, but does not seem to be used.

Partition  Attrs   Start Sector    End Sector  # of Sectors System
/dev/sdb1   +  R              0     3,815,079     3,815,080 Data partition (Windows/Linux)
/dev/sdb2   +  R      3,737,268     3,741,939         4,672 Data partition (Windows/Linux)

Attributes: R=Required, N=No Block IO, B=Legacy BIOS Bootable, +=More bits set

"blkid" output: ________________________________________________________________

Device           UUID                                   TYPE       LABEL

/dev/loop0                                              squashfs   
/dev/loop1                                              squashfs   
/dev/loop2                                              squashfs   
/dev/loop3                                              squashfs   
/dev/loop4                                              squashfs   
/dev/loop5                                              squashfs   
/dev/loop6                                              squashfs   
/dev/loop7                                              squashfs   
/dev/sda2        ac3b70ee-5ea2-4bff-925e-2bfdd2574a58   ext4       
/dev/sda3        0A146176146165A3                       ntfs       System Reserved
/dev/sda4        020C70DE0C70CDE3                       ntfs       
/dev/sda5        3a8dabde-ff2c-46d4-8521-2ecb9e2e06e3   swap       
/dev/sdb1        2018-07-25-03-21-56-00                 iso9660    Ubuntu 18.04.1 LTS amd64
/dev/sdb2        0D5F-1DB6                              vfat       

========================= "ls -l /dev/disk/by-id" output: ======================

total 0
lrwxrwxrwx 1 root root  9 Dec 14 14:08 ata-ST500LM021-1KJ152_W624KNNP -> ../../sda
lrwxrwxrwx 1 root root 10 Dec 14 14:08 ata-ST500LM021-1KJ152_W624KNNP-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Dec 14 14:08 ata-ST500LM021-1KJ152_W624KNNP-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Dec 14 14:08 ata-ST500LM021-1KJ152_W624KNNP-part3 -> ../../sda3
lrwxrwxrwx 1 root root 10 Dec 14 14:08 ata-ST500LM021-1KJ152_W624KNNP-part4 -> ../../sda4
lrwxrwxrwx 1 root root 10 Dec 14 14:08 ata-ST500LM021-1KJ152_W624KNNP-part5 -> ../../sda5
lrwxrwxrwx 1 root root  9 Dec 14 14:07 usb-SanDisk_Cruzer_Switch_4C532000060807117464-0:0 -> ../../sdb
lrwxrwxrwx 1 root root 10 Dec 14 14:07 usb-SanDisk_Cruzer_Switch_4C532000060807117464-0:0-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 Dec 14 14:07 usb-SanDisk_Cruzer_Switch_4C532000060807117464-0:0-part2 -> ../../sdb2
lrwxrwxrwx 1 root root  9 Dec 14 14:08 wwn-0x5000c50082dcbba1 -> ../../sda
lrwxrwxrwx 1 root root 10 Dec 14 14:08 wwn-0x5000c50082dcbba1-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Dec 14 14:08 wwn-0x5000c50082dcbba1-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Dec 14 14:08 wwn-0x5000c50082dcbba1-part3 -> ../../sda3
lrwxrwxrwx 1 root root 10 Dec 14 14:08 wwn-0x5000c50082dcbba1-part4 -> ../../sda4
lrwxrwxrwx 1 root root 10 Dec 14 14:08 wwn-0x5000c50082dcbba1-part5 -> ../../sda5

================================ Mount points: =================================

Device           Mount_Point              Type       Options

/dev/loop0       /rofs                    squashfs   (ro,noatime)
/dev/sdb         /cdrom                   iso9660    (ro,noatime,nojoliet,check=s,map=n,blocksize=2048)


======================== Unknown MBRs/Boot Sectors/etc: ========================

Unknown MBR on /dev/sdb

00000000  45 52 08 00 00 00 90 90  00 00 00 00 00 00 00 00  |ER..............|
00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000020  33 ed fa 8e d5 bc 00 7c  fb fc 66 31 db 66 31 c9  |3......|..f1.f1.|
00000030  66 53 66 51 06 57 8e dd  8e c5 52 be 00 7c bf 00  |fSfQ.W....R..|..|
00000040  06 b9 00 01 f3 a5 ea 4b  06 00 00 52 b4 41 bb aa  |.......K...R.A..|
00000050  55 31 c9 30 f6 f9 cd 13  72 16 81 fb 55 aa 75 10  |U1.0....r...U.u.|
00000060  83 e1 01 74 0b 66 c7 06  f3 06 b4 42 eb 15 eb 02  |...t.f.....B....|
00000070  31 c9 5a 51 b4 08 cd 13  5b 0f b6 c6 40 50 83 e1  |1.ZQ....[...@P..|
00000080  3f 51 f7 e1 53 52 50 bb  00 7c b9 04 00 66 a1 b0  |?Q..SRP..|...f..|
00000090  07 e8 44 00 0f 82 80 00  66 40 80 c7 02 e2 f2 66  |..D.....f@.....f|
000000a0  81 3e 40 7c fb c0 78 70  75 09 fa bc ec 7b ea 44  |.>@|..xpu....{.D|
000000b0  7c 00 00 e8 83 00 69 73  6f 6c 69 6e 75 78 2e 62  ||.....isolinux.b|
000000c0  69 6e 20 6d 69 73 73 69  6e 67 20 6f 72 20 63 6f  |in missing or co|
000000d0  72 72 75 70 74 2e 0d 0a  66 60 66 31 d2 66 03 06  |rrupt...f`f1.f..|
000000e0  f8 7b 66 13 16 fc 7b 66  52 66 50 06 53 6a 01 6a  |.{f...{fRfP.Sj.j|
000000f0  10 89 e6 66 f7 36 e8 7b  c0 e4 06 88 e1 88 c5 92  |...f.6.{........|
00000100  f6 36 ee 7b 88 c6 08 e1  41 b8 01 02 8a 16 f2 7b  |.6.{....A......{|
00000110  cd 13 8d 64 10 66 61 c3  e8 1e 00 4f 70 65 72 61  |...d.fa....Opera|
00000120  74 69 6e 67 20 73 79 73  74 65 6d 20 6c 6f 61 64  |ting system load|
00000130  20 65 72 72 6f 72 2e 0d  0a 5e ac b4 0e 8a 3e 62  | error...^....>b|
00000140  04 b3 07 cd 10 3c 0a 75  f1 cd 18 f4 eb fd 00 00  |.....f....|
000001c0  01 00 00 74 e0 fa 00 00  00 00 e0 36 3a 00 00 fe  |...t.......6:...|
000001d0  ff ff ef fe ff ff b4 06  39 00 40 12 00 00 00 00  |........9.@.....|
000001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
00000200


/dev/sdb1: unknown GPT attributes
1000000000000001

/dev/sdb2: unknown GPT attributes
1000000000000001
Unknown BootLoader on sdb1

00000000  45 52 08 00 00 00 90 90  00 00 00 00 00 00 00 00  |ER..............|
00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000020  33 ed fa 8e d5 bc 00 7c  fb fc 66 31 db 66 31 c9  |3......|..f1.f1.|
00000030  66 53 66 51 06 57 8e dd  8e c5 52 be 00 7c bf 00  |fSfQ.W....R..|..|
00000040  06 b9 00 01 f3 a5 ea 4b  06 00 00 52 b4 41 bb aa  |.......K...R.A..|
00000050  55 31 c9 30 f6 f9 cd 13  72 16 81 fb 55 aa 75 10  |U1.0....r...U.u.|
00000060  83 e1 01 74 0b 66 c7 06  f3 06 b4 42 eb 15 eb 02  |...t.f.....B....|
00000070  31 c9 5a 51 b4 08 cd 13  5b 0f b6 c6 40 50 83 e1  |1.ZQ....[...@P..|
00000080  3f 51 f7 e1 53 52 50 bb  00 7c b9 04 00 66 a1 b0  |?Q..SRP..|...f..|
00000090  07 e8 44 00 0f 82 80 00  66 40 80 c7 02 e2 f2 66  |..D.....f@.....f|
000000a0  81 3e 40 7c fb c0 78 70  75 09 fa bc ec 7b ea 44  |.>@|..xpu....{.D|
000000b0  7c 00 00 e8 83 00 69 73  6f 6c 69 6e 75 78 2e 62  ||.....isolinux.b|
000000c0  69 6e 20 6d 69 73 73 69  6e 67 20 6f 72 20 63 6f  |in missing or co|
000000d0  72 72 75 70 74 2e 0d 0a  66 60 66 31 d2 66 03 06  |rrupt...f`f1.f..|
000000e0  f8 7b 66 13 16 fc 7b 66  52 66 50 06 53 6a 01 6a  |.{f...{fRfP.Sj.j|
000000f0  10 89 e6 66 f7 36 e8 7b  c0 e4 06 88 e1 88 c5 92  |...f.6.{........|
00000100  f6 36 ee 7b 88 c6 08 e1  41 b8 01 02 8a 16 f2 7b  |.6.{....A......{|
00000110  cd 13 8d 64 10 66 61 c3  e8 1e 00 4f 70 65 72 61  |...d.fa....Opera|
00000120  74 69 6e 67 20 73 79 73  74 65 6d 20 6c 6f 61 64  |ting system load|
00000130  20 65 72 72 6f 72 2e 0d  0a 5e ac b4 0e 8a 3e 62  | error...^....>b|
00000140  04 b3 07 cd 10 3c 0a 75  f1 cd 18 f4 eb fd 00 00  |.....f....|
000001c0  01 00 00 74 e0 fa 00 00  00 00 e0 36 3a 00 00 fe  |...t.......6:...|
000001d0  ff ff ef fe ff ff b4 06  39 00 40 12 00 00 00 00  |........9.@.....|
000001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000001f0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 55 aa  |..............U.|
00000200


=============================== StdErr Messages: ===============================

File descriptor 10 (/proc/7892/mountinfo) leaked on lvs invocation. Parent PID 15283: bash
File descriptor 63 (pipe:[89099]) leaked on lvs invocation. Parent PID 15283: bash

ADDITIONAL INFORMATION :
=================== log of boot-repair 20181214_1407 ===================
boot-repair version : 4ppa65
boot-sav version : 4ppa65
boot-sav-extra version : 4ppa65
glade2script version : 3.2.3~ppa4
grub-probe: error: cannot find a GRUB drive for /dev/sdb1.  Check your device.map.
Warning: The driver descriptor says the physical block size is 2048 bytes, but Linux says it is 512 bytes.
Partition 1 does not start on physical sector boundary.
boot-repair is executed in live-session (Ubuntu 18.04.1 LTS, bionic, Ubuntu, x86_64)
CPU op-mode(s):      32-bit, 64-bit
file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --- maybe-ubiquity
ls: cannot access '/home/usr/.config': No such file or directory

=================== os-prober:
/dev/sda3:Windows 7:Windows:chain

=================== blkid:
/dev/sda2: UUID="ac3b70ee-5ea2-4bff-925e-2bfdd2574a58" TYPE="ext4" PARTUUID="26508a31-02"
/dev/sda3: LABEL="System Reserved" UUID="0A146176146165A3" TYPE="ntfs" PARTUUID="26508a31-03"
/dev/sda4: UUID="020C70DE0C70CDE3" TYPE="ntfs" PARTUUID="26508a31-04"
/dev/loop0: TYPE="squashfs"
/dev/loop1: TYPE="squashfs"
/dev/loop2: TYPE="squashfs"
/dev/loop3: TYPE="squashfs"
/dev/loop4: TYPE="squashfs"
/dev/loop5: TYPE="squashfs"
/dev/loop6: TYPE="squashfs"
/dev/loop7: TYPE="squashfs"
/dev/sda5: UUID="3a8dabde-ff2c-46d4-8521-2ecb9e2e06e3" TYPE="swap" PARTUUID="26508a31-05"
/dev/sdb1: UUID="2018-07-25-03-21-56-00" LABEL="Ubuntu 18.04.1 LTS amd64" TYPE="iso9660" PTUUID="663eb4c4" PTTYPE="dos" PARTUUID="663eb4c4-01"
/dev/sdb2: SEC_TYPE="msdos" UUID="0D5F-1DB6" TYPE="vfat" PARTUUID="663eb4c4-02"


1 disks with OS, 1 OS : 0 Linux, 0 MacOS, 1 Windows, 0 unknown type OS.

Windows not detected by os-prober on sda4.
Partition 1 does not start on physical sector boundary.
Partition 1 does not start on physical sector boundary.

=================== UEFI/Legacy mode:
This live-session is not in EFI-mode.
EFI in dmesg.
[    0.000000] ACPI: UEFI 0x00000000D9F0D720 000042 (v01                 00000000      00000000)
SecureBoot maybe enabled.


=================== PARTITIONS & DISKS:
sda2    : sda,  maybesepboot,   no-grubenv  nogrub, no-docgrub, no-update-grub, 32, no-boot,    no-os,  not--efi--part, part-has-no-fstab,  part-has-no-fstab,  no-nt,  no-winload, no-recov-nor-hid,   no-bmgr,    notwinboot, nopakmgr,   nogrubinstall,  no---usr,   part-has-no-fstab,  not-sep-usr,    standard,   farbios,    notbiosboot, /mnt/boot-sav/sda2.
sda3    : sda,  not-sepboot,    no-grubenv  nogrub, no-docgrub, no-update-grub, 32, no-boot,    is-os,  not--efi--part, part-has-no-fstab,  part-has-no-fstab,  no-nt,  no-winload, no-recov-nor-hid,   bootmgr,    is-winboot, nopakmgr,   nogrubinstall,  no---usr,   part-has-no-fstab,  not-sep-usr,    standard,   farbios,    notbiosboot, /mnt/boot-sav/sda3.
sda4    : sda,  not-sepboot,    no-grubenv  nogrub, no-docgrub, no-update-grub, 32, no-boot,    is-os,  not--efi--part, part-has-no-fstab,  part-has-no-fstab,  no-nt,  haswinload, no-recov-nor-hid,   no-bmgr,    notwinboot, nopakmgr,   nogrubinstall,  no---usr,   part-has-no-fstab,  not-sep-usr,    standard,   farbios,    notbiosboot, /mnt/boot-sav/sda4.

sda : not-GPT,  BIOSboot-not-needed,    has-no-EFIpart,     not-usb,    not-mmc, has-os,    2046 sectors * 512 bytes


=================== parted -lm:

BYT;
/dev/sda:500GB:scsi:512:4096:msdos:ATA ST500LM021-1KJ15:;
1:1048kB:102GB:102GB:::;
5:94.0GB:102GB:8000MB:linux-swap(v1)::;
2:152GB:252GB:100GB:ext4::;
3:252GB:252GB:105MB:ntfs::boot;
4:252GB:357GB:105GB:ntfs::;

BYT;
/dev/sdb:8004MB:scsi:512:512:unknown:SanDisk Cruzer Switch:;

=================== lsblk:
KNAME TYPE FSTYPE     SIZE LABEL
loop0 loop squashfs   1.8G
loop1 loop squashfs  86.9M
loop2 loop squashfs  34.7M
loop3 loop squashfs 140.9M
loop4 loop squashfs   2.3M
loop5 loop squashfs    13M
loop6 loop squashfs  14.5M
loop7 loop squashfs   3.7M
sda   disk          465.8G
sda1  part              1K
sda2  part ext4      93.1G
sda3  part ntfs       100M System Reserved
sda4  part ntfs      97.6G
sda5  part swap       7.5G
sdb   disk iso9660    7.5G Ubuntu 18.04.1 LTS amd64
sdb1  part iso9660    1.8G Ubuntu 18.04.1 LTS amd64
sdb2  part vfat       2.3M Ubuntu 18.04.1 LTS amd64

KNAME ROTA RO RM STATE   MOUNTPOINT
loop0    1  1  0         /rofs
loop1    1  1  0         /snap/core/4917
loop2    1  1  0         /snap/gtk-common-themes/319
loop3    1  1  0         /snap/gnome-3-26-1604/70
loop4    1  1  0         /snap/gnome-calculator/180
loop5    1  1  0         /snap/gnome-characters/103
loop6    1  1  0         /snap/gnome-logs/37
loop7    1  1  0         /snap/gnome-system-monitor/51
sda      1  0  0 running
sda1     1  0  0
sda2     1  0  0         /mnt/boot-sav/sda2
sda3     1  0  0         /mnt/boot-sav/sda3
sda4     1  0  0         /mnt/boot-sav/sda4
sda5     1  0  0         [SWAP]
sdb      1  0  1 running /cdrom
sdb1     1  0  1
sdb2     1  0  1


=================== mount:
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=1948892k,nr_inodes=487223,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=394016k,mode=755)
/dev/sdb on /cdrom type iso9660 (ro,noatime,nojoliet,check=s,map=n,blocksize=2048)
/dev/loop0 on /rofs type squashfs (ro,noatime)
/cow on / type overlay (rw,relatime,lowerdir=//filesystem.squashfs,upperdir=/cow/upper,workdir=/cow/work)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)
cgroup on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/rdma type cgroup (rw,nosuid,nodev,noexec,relatime,rdma)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=25,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=15764)
mqueue on /dev/mqueue type mqueue (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
tracefs on /sys/kernel/debug/tracing type tracefs (rw,relatime)
configfs on /sys/kernel/config type configfs (rw,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,relatime)
tmpfs on /run/user/999 type tmpfs (rw,nosuid,nodev,relatime,size=394012k,mode=700,uid=999,gid=999)
gvfsd-fuse on /run/user/999/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=999,group_id=999)
/var/lib/snapd/snaps/core_4917.snap on /snap/core/4917 type squashfs (ro,nodev,relatime,x-gdu.hide)
/var/lib/snapd/snaps/gtk-common-themes_319.snap on /snap/gtk-common-themes/319 type squashfs (ro,nodev,relatime,x-gdu.hide)
/var/lib/snapd/snaps/gnome-3-26-1604_70.snap on /snap/gnome-3-26-1604/70 type squashfs (ro,nodev,relatime,x-gdu.hide)
/var/lib/snapd/snaps/gnome-calculator_180.snap on /snap/gnome-calculator/180 type squashfs (ro,nodev,relatime,x-gdu.hide)
/var/lib/snapd/snaps/gnome-characters_103.snap on /snap/gnome-characters/103 type squashfs (ro,nodev,relatime,x-gdu.hide)
/var/lib/snapd/snaps/gnome-logs_37.snap on /snap/gnome-logs/37 type squashfs (ro,nodev,relatime,x-gdu.hide)
/var/lib/snapd/snaps/gnome-system-monitor_51.snap on /snap/gnome-system-monitor/51 type squashfs (ro,nodev,relatime,x-gdu.hide)
/dev/sda2 on /mnt/boot-sav/sda2 type ext4 (rw,relatime,data=ordered)
/dev/sda3 on /mnt/boot-sav/sda3 type fuseblk (rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096)
/dev/sda4 on /mnt/boot-sav/sda4 type fuseblk (rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096)


=================== ls:
/sys/block/sda (filtered):  alignment_offset bdi capability dev device discard_alignment events events_async events_poll_msecs ext_range hidden holders inflight integrity power queue range removable ro sda1 sda2 sda3 sda4 sda5 size slaves stat subsystem trace uevent
/sys/block/sdb (filtered):  alignment_offset bdi capability dev device discard_alignment events events_async events_poll_msecs ext_range hidden holders inflight integrity power queue range removable ro sdb1 sdb2 size slaves stat subsystem trace uevent
/dev (filtered):  autofs block bsg btrfs-control bus char console core cpu cpu_dma_latency cuse disk dri drm_dp_aux0 drm_dp_aux1 ecryptfs fb0 fd full fuse hidraw0 hpet hugepages hwrng i2c-0 i2c-1 i2c-2 i2c-3 i2c-4 i2c-5 i2c-6 i2c-7 initctl input kmsg kvm lightnvm log mapper mcelog media0 mei0 mem memory_bandwidth mqueue net network_latency network_throughput null port ppp psaux ptmx pts random rfkill rtc rtc0 sda sda1 sda2 sda3 sda4 sda5 sdb sdb1 sdb2 sg0 sg1 shm snapshot snd stderr stdin stdout uhid uinput urandom userio v4l vfio vga_arbiter vhci vhost-net vhost-vsock video0 wmi zero
ls /dev/mapper:  control

=================== df -Th:

Filesystem     Type      Size  Used Avail Use% Mounted on
udev           devtmpfs  1.9G     0  1.9G   0% /dev
tmpfs          tmpfs     385M  1.7M  384M   1% /run
/dev/sdb       iso9660   1.9G  1.9G     0 100% /cdrom
/dev/loop0     squashfs  1.8G  1.8G     0 100% /rofs
/cow           overlay   1.9G  462M  1.5G  24% /
tmpfs          tmpfs     1.9G   30M  1.9G   2% /dev/shm
tmpfs          tmpfs     5.0M  8.0K  5.0M   1% /run/lock
tmpfs          tmpfs     1.9G     0  1.9G   0% /sys/fs/cgroup
tmpfs          tmpfs     1.9G  520K  1.9G   1% /tmp
tmpfs          tmpfs     385M   48K  385M   1% /run/user/999
/dev/loop1     squashfs   87M   87M     0 100% /snap/core/4917
/dev/loop2     squashfs   35M   35M     0 100% /snap/gtk-common-themes/319
/dev/loop3     squashfs  141M  141M     0 100% /snap/gnome-3-26-1604/70
/dev/loop4     squashfs  2.4M  2.4M     0 100% /snap/gnome-calculator/180
/dev/loop5     squashfs   13M   13M     0 100% /snap/gnome-characters/103
/dev/loop6     squashfs   15M   15M     0 100% /snap/gnome-logs/37
/dev/loop7     squashfs  3.8M  3.8M     0 100% /snap/gnome-system-monitor/51
/dev/sda2      ext4       92G   28G   60G  32% /mnt/boot-sav/sda2
/dev/sda3      fuseblk   100M   25M   76M  25% /mnt/boot-sav/sda3
/dev/sda4      fuseblk    98G   25G   73G  26% /mnt/boot-sav/sda4

=================== fdisk -l:
Disk /dev/loop0: 1.8 GiB, 1864450048 bytes, 3641504 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop1: 86.9 MiB, 91099136 bytes, 177928 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop2: 34.7 MiB, 36323328 bytes, 70944 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop3: 140.9 MiB, 147722240 bytes, 288520 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop4: 2.3 MiB, 2433024 bytes, 4752 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop5: 13 MiB, 13619200 bytes, 26600 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop6: 14.5 MiB, 15196160 bytes, 29680 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop7: 3.7 MiB, 3887104 bytes, 7592 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/sda: 465.8 GiB, 500107862016 bytes, 976773168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x26508a31

Device     Boot     Start       End   Sectors  Size Id Type
/dev/sda1            2046 199313407 199311362   95G  5 Extended
/dev/sda2       296970240 492281855 195311616 93.1G 83 Linux
/dev/sda3  *    492281856 492486655    204800  100M  7 HPFS/NTFS/exFAT
/dev/sda4       492486656 697081855 204595200 97.6G  7 HPFS/NTFS/exFAT
/dev/sda5       183689216 199313407  15624192  7.5G 82 Linux swap / Solaris

Partition table entries are not in disk order.


Disk /dev/sdb: 7.5 GiB, 8004304896 bytes, 15633408 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x663eb4c4

Device     Boot   Start     End Sectors  Size Id Type
/dev/sdb1  *          0 3815135 3815136  1.8G  0 Empty
/dev/sdb2       3737268 3741939    4672  2.3M ef EFI (FAT-12/16/32)



=================== Recommended repair
The default repair of the Boot-Repair utility will restore the [(generic mbr)] MBR in sda, and make it boot on sda3.
Additional repair will be performed: unhide-bootmenu-10s   fix-windows-boot


Quantity of real Windows: 1
Will restore the MBR_TO_RESTORE : sda (generic mbr) into sda
dd if=/usr/lib/syslinux/mbr/mbr.bin of=/dev/sda
0+1 records in
0+1 records out

Boot successfully repaired.

You can now reboot your computer.

marked as duplicate by Kulfy, Fabby, vidarlo, LnxSlck, user535733 Jun 19 at 2:55

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

0

First try to open boot options menu by pressing f9[some devices may have different key] and then select ubuntu from there. Once your ubuntu succesfully boots up. open a terminal and check if grub is installed or not

sudo apt-get install grub

and finally

sudo update-grub

This command identifies if there is any other OS apart from ubuntu and adds that OS to grub list

Not the answer you're looking for? Browse other questions tagged or ask your own question.