My partitions are as follows:

900 MB FAT32 (contains .bat,kernel.sys,bootmgr,bootsect.bak,fdosboot.bin ... etc. files)
70 GB NTFS (Windows 7) (also contains bootmgr,kernel.sys,bootsect.bak after using boot-repair)
80 GB ext4 (Ubuntu)
315 GB NTFS (Personal data)

I had dual boot problems after removing ubuntu incorrectly and after using boot-repair I got it solved.The grub menu previously(before problem) showed Win7 as on /dev/sda1,which is the FAT32 partition.After using boot-repair, it shows two options for Win7.One on /dev/sda1 (goes back to the error I was experiencing) and another on /dev/sda2 (actual Win7 installation) which boots me up with Win7.

Should I consider it safe to just remove the FAT32 partition?
I am not using ubuntu much nowadays and again thinking to uninstall it.Could you suggest a good way of not messing up the grub and going back to the Windows Bootloader after removal of Ubuntu? (WinRE bootrec commands do not work)

1 Answer 1


Short answer: If it's working fine now, better leave it as it is.

This question is more about the Windows boot setup. Please take a look at this answer on superuser.

The FAT partition is meant to be the EFI System Partition. Even if your computer is not UEFI enabled or defaults to traditional MBR based boot the Windows installation disk as well as OEM installations create two partitions:

  • the first one marked as system partition where the bootloader files and configuration for EFI and MBR boot are stored
  • the second one where the operating system is installed (and in some cases an individual backup boot configuration for MBR and EFI, that's why you can boot directly from the second partition, or via chainloader)

You could delete the first partition and move the second partition the use the free space, but 900 MB isn't worth the hassle that will follow. You will need to reinstall the bootloader and bootconfiguration to the second partition (the setup becomes invalid when you move the partition) via

bootrec /fixboot


bcdboot c:\Windows /l en-gb /s c: /f ALL

commands from the Windows installation disk. Take a look at the above mentioned Superuser answer and the GParted FAQ. You will probably need to mark the second partition as system or boot partition to make the above listed commands work. Then you need to install Grub again and probably everything will be fine again. If Grub's os-prober and boot-repair fail to find your Windows installation or the entry is not properly configured you need to write a customized entry.

For example this is a configuration from my laptop that is booting UEFI Grub from a GPT partitioned disk and starting Windows 8 from another MBR partitioned disk by running the EFI Windows bootmanager:

$ cat /etc/grub.d/40_custom 
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

menuentry "Windows 8 (UEFI configuration on system drive)" {
        insmod part_msdos
        insmod ntfs
        insmod search_fs_uuid
        insmod chain

        set root='hd0,msdos4'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos4 --hint-efi=hd0,msdos4 --hint-baremetal=ahci0,msdos4  2ACC7043CC700B79
          search --no-floppy --fs-uuid --set=root 2ACC7043CC700B79

        chainloader /EFI/Microsoft/Boot/bootmgfw.efi

It's really not worth the hassle and risk. Instead you could do a clean and proper reinstall of Windows to one partition, and reinstall and configure Grub afterwards.

  • Helped me with detail.I have a similar 'menuentry' for Windows,but without EFI.I was thinking of a clean install but I suppose I should leave it as such.@LiveWireBT
    – Siddharth
    Oct 3, 2013 at 15:42

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