I bought my notebook with Windows 7. I, one day, decided to install Linux. I did it, but I am unable to boot Windows. When I turn the computer on, I get to GRUB. If I choose Linux, I'm good to go, but if I choose Windows 7 instead, I get to a "grub rescue" prompt with a message saying:

Unknown file system

Please, help me. I really don't know what to do.


Sorry for my delay. I wasn't able to access the internet in the past few days. None of these worked, and I had to reinstall Windows using the Recovery CD I made on the previous installation.

Thanks everyone for your support.

  • Hmmm. It can be fixed without re installation as it as a common problem faced by many new users. Anyways if you face it again , know the solution given by nobody :) – mac Apr 9 '12 at 7:18

Simply try to repair your boot (grub) with boot-repair CD. You will find all the explications here. https://help.ubuntu.com/community/Boot-Repair

  • I wasn't able to restore via boot-repair. I don't know if I made something wrong, but it didn't work. – Patrick Villela Jan 21 '12 at 23:27
  • Did you boot with the CD of did you try to execute with Ubuntu? What is happening? – Julien Chau Jan 22 '12 at 9:10

There are lots of possibilities that can cause to this kind of problem. It mainly depends on how you installed the operating system (Linux in this case). Did you install it side-by-side with Windows? OR Did you do some sort of altering the partition table that was there before you install Linux.

I highly suspect that you have done some sort of altering (i.e. shrinking or/and creating new partition etc.) to the partition table and hence to the partition where Windows was installed. As result of that your NTFS partition (Windows partition) might have corrupted. You can try to repair your NTFS partition but, first try these things.

Assuming you're using later version of Debian, Ubuntu or their derived distribution and hence you have Grub 2 installed in you system:

run in terminal sudo update-grub2 enter your sudo password when prompted. See whether is there any error or abnormal output. (I have a dual boot system with Windows 7. So typical output would be something as shown below)

typical Grub 2 output for a dual boot system with Windows

Assuming things went well, reboot the system and try to load Windows 7. If you get the previous message (the one you have mentioned in the question) then, you have to go the next step, repairing your Windows partition.

If you can mount your NTFS partition it is better (and important) to backup any important data in that partition.

Now install some packages (if they are not already in your system). Type in terminal sudo apt-get install ntfsprogs. Try to repair / resize your NTFS partition. Commands you need to type depends on what you wanna achieve at the end. So, before you do any thing, please go through the man pages of ntfsprogs

If nothing work for you then, you need to reinstall Windows and repair Grub boot loader (since Windows boot loader overwrites Grub (MBR)) if you want to login to Linux as well.

Here are some good links regarding Dual Boot Windows 7 with Ubuntu. Hope these might help you :)

link 1

link 2

link 3

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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