We see chronic problems with GRUB corrupting Windows 7 beyond repair when it is on the same HD. Best if you can to boot them on separate HD's via BIOS and not use GRUB at all.
The error appear to be boot sector corruption which is exactly what GRUB does to Windows 7, however it doesn't seem bad enough to affect performance further yet. I'd work on getting separate HD's before going as far as to reinstall.
If SFC won't run from elevated Windows 7 Command Line, or from Recovery options Command Line via F8, DVD or Repair CD (making sure to use the Windows 7 drive letter which WinRE presents which might be different), due to a pending repair, then try running Startup Repair from DVD/Repair CD first.
If you clean reinstall be sure to wipe the HD of all GRUB corruption using tutorial in my link below.
Tips for getting a purrfect Windows 7 clean reinstall - use the ones which apply: re-install windows 7