I have been using Ubuntu 16.04 alongside Windows 7 very smoothly for several years. But something went wrong and after using Boot-Repair to restore the GRUB load Menu.

  1. I can't load Windows 7 anymore
  2. After trying to restore Windows 7 using the Installing Disk, I noticed that it was unable to detect the Hard Disk and the partition where Windows 7 supposed to be installed.
  3. But Ubuntu still detects the OS Partition
  4. I ran GParted to try to see what happened this messaged poped-up:

"The driver descriptor says the physical block size is 2048 bytes, but Linux says it is 512 bytes."

After exploring my OS Partition (/dev/sda3)I found this Warning message:

"Unable to read the contents of this file system! Because of this some operations may be unavailable. The cause might be a missing software package. The following list of software packages is required for ntfs file system support: ntfs-3g / ntfsprogs."

  1. GParted was unable to solve repair file system (nfts) on /dev/sda3;

  2. Additional information:

" Disk /dev/sda: 698.7 GiB, 750156374016 bytes, 1465149168 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: 0xdd6865b6

    Device     Boot      Start        End    Sectors  Size Id Type
    /dev/sda1               63      80324      80262 39.2M  6 FAT16
    /dev/sda2            81920   25563135   25481216 12.2G  7 HPFS/NTFS/exFAT
    /dev/sda3         25563136 1332019199 1306456064  623G  7 HPFS/NTFS/exFAT
    /dev/sda4       1332021246 1465147391  133126146 63.5G  5 Extended
    /dev/sda5       1400381440 1431629823   31248384 14.9G 82 Linux swap / Solaris
    /dev/sda6       1431631872 1465147391   33515520   16G 83 Linux
    /dev/sda7       1332021248 1400381439   68360192 32.6G 83 Linux

Partition 1 does not start on physical sector boundary. Partition 4 does not start on physical sector boundary. Partition table entries are not in disk order."

Please could anyone assist me? I'm at the end of my rope here

How could I restore Windows 7 and fix my problem ?

1 Answer 1


The following GParted message is very troubling:

The driver descriptor says the physical block size is 2048 bytes, but Linux says it is 512 bytes.

Most hard disks have 512-byte logical sectors. Older hard disks also have 512-byte physical sectors, but many newer ones have 4096-byte physical sectors, each of which is "translated" into eight 512-byte sectors. A few modern disks have 4096-byte physical and logical sectors. The only disks I know of with 2048-byte sectors are optical disks -- CDs, DVDs, magneto-optical (MO) disks, and variants of these like CD-Rs. Thus, the fact that GParted is saying that the physical block (sector) size is 2048 on a regular hard disk is very strange.

The sector size is not something you can change; it's fixed in the hardware, at least on modern hard disks. Thus, the fact that GParted is claiming the physical sector size is something strange points to a hardware failure. If so, you'll need to replace your disk. Perhaps doing a low-level copy of the original filesystem to a new disk will make it readable again. OTOH, your fdisk output indicates a standard 512-byte sector size (both physical and logical). Thus, it could be that you've found a bug in GParted (or the libparted library upon which it relies).

Another possibility is that the GParted message is referring to the size of filesystem data blocks (aka "cluster size"). According to this Microsoft page, these can be 512 bytes to 64 KiB for NTFS, depending on what OS version created the filesystem and what the filesystem's size is. If the NTFS data structures have become damaged, it's conceivable that Windows would become unbootable and Linux utilities would also be unable to cope. If this hypothesis is correct, there's a chance that an NTFS repair utility could fix the filesystem. Note that there are no good NTFS repair utilities for Linux. The ntfsfix tool just does a few trivial checks and then flags the filesystem for repair in Windows. To properly repair this filesystem, you'd need to boot a Windows emergency disk and then run CHKDSK on it, or some other Windows filesystem-repair tool. If you think this is the cause, I recommend asking on a Windows forum for more help, since NTFS repair is a Windows issue, not an Ubuntu issue.

In any event, I strongly recommend that you first back up the entire disk, or at least the Windows partition. This will require a target disk that's at least as large as the source disk or partition. A command like the following should do the trick:

sudo dd if=/dev/sda of=/path/to/lots/of/space/sda.img

This will back up the entire /dev/sda device to /path/to/lots/of/space/sda.img; you'd mount your backup medium to /path or some subdirectory on the way to sda.img. (You'd probably change the name of the mount point, of course.)

You could use a similar command to copy the entire disk; you'd just use of=/dev/sdb rather than an of= value that points to a file on a filesystem. Be very careful with dd, though, especially when you target a whole disk device; if you reverse the if= and of= options, or otherwise provide incorrect options, you can easily trash your original disk.

  • Hi @RodSmith I don´t believe it is a HD faliure. I think something or some option I might have selected changed the partition configuration. Do yopu think I is related to Boot-Flags? I´ll try to post later the results from "Create BootInfo Summary". May 25, 2017 at 16:37

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