I recently installed 11.10 on a new partition on my Windows 7 PC, and it works perfectly. But when I want to boot Windows 7 from the grub boot menu, it just says
unknown file system, grub rescue.
Windows recovery says there is nothing wrong with it, an I can access all the files through Ubuntu. The Ubuntu Disk Utility says that the Windows 7 partition file system is NOT clean.
How do I get my Windows 7 back?