I have a similar problem posted in the Dutch forum http://forums.linuxmint.com/viewtopic.php?f=67&t=95236
After installing Linux Mint the dual-boot option in grub with Windows7 won't work anymore. I'm unable to boot my Windows7
and I've tried everything to repare this in Linux and Windows. My windows mbr was damaged and unrepairable.
After trying all the options mentioned here now my grub is also broke and also unrepairable.
When you use the option
"Purge and reinstall the Grub of" from the Boot-Repair tool, first make a copy of your boot/grub folder to a usb-stick.
When you use this option the Boot-Repair tool will delete all the files in your boot/grub folder and then it should reinstall
the new files. To me this went terribly wrong. It kept telling me that my boot/grub folder wasn't empty although it was and
therefore it wouldn't proceed with installing the new grub-files. This means that I now couldn't boot Linux Mint also!
In my search for a solution to reinstall grub I found a tool called Rescatux at this link http://www.supergrubdisk.org/category/download/rescatuxdownloads/
This program would be able to repair grub and also the mbr from windows. When you still can run Linux Mint then you should download this iso from the link
and then burn this to a blank cd. This is a bootable cd and after reboot the program Rescapp will appear. There are several options like Grub and Windows and when you
select one then a complete explanation appears with what it could do. To repair your windows mbr you have to select Windows(+). From there you can find how to
repair your windows mbr. After thats finished, you should reboot your pc with a Windows7 recovery disk and when you choose to repair your computer you should
now be able to see and select your windows7 operating system. Select this and press next and then select the command prompt option. Here you enter the command
- Code: Select all
You now should see the message "The operation completed successfully". Now you can reboot without any boot-cd and your Windows will finally start again!
After this you will now have to find a solution to restore the dual-boot with Linux Mint again, but maybe this could be explained by someone else how this should be properly done.
For me, I will have to found another solution becausse my Mint installation could not be restored due to the lost grub-files. Perhaps I will have to completely reinstall Linux Mint
from scratch, but maybe someone can explain me how I should do this best without any hassle.
I hope that this will help you and that you can repair your Windows boot like I did.