Windows 7: Recover Windows 7 boot on dual boot system with GRUB masterboot

Hi,
I have a dual-boot system Ubuntu/Windows 7. The Master boot loader is GRUB.
It worked fine until yesterday when, for some reason, Windows 7 refused to load anymore. I tried to repair with chkdsk, found and repaired some disk errors, but now the boot loader is damaged. The problem I have is that after selecting Windows from the GRUB list I get the installed version entry but I can't have access to Repair through F8 and thus I am not able to continue on the installation DVD. The problem I think would be simple, by writing a new boot using bootrec, but I don't have access to the console.
I've seen a solution/tutorial on this forum except that it requires to remove Linux, which is not at all my scope.
Thanks

1) Use the Rebuild BCD in this tutorial:
How to use the Bootrec.exe tool in the Windows Recovery Environment to troubleshoot and repair startup issues in Windows



2) Fix MBR.



NOTE: As you have Linux installed, the above only works for 1 in 1000, must likely you will need to reinstall.
Good luck.

Have a look at this. It requires a live Linux CD: http://www.howtogeek.com/howto/ubuntu/reinstall-ubuntu-grub-bootloader-after-windows-wipes-it-out/

Interesting, I've just learned that Microsoft wants me to pay to fix their bug. Good to know guys, but business is business.
Thanks to all who answered, seems like there's no solution

IMO, Linux is the bug, in Dual booting.

Grub can be a pain in the neck. That is why I always install Linux on a seperate physical disk and disconnect the Windows disk during the Linux installation. The Grub cannot clobber the Windows bootmgr - and that works also the same the other way around (Linux first, Windows second). I then switch between the 2 systems with the BIOS boot sequence.

On another system (a laptop where I have only 1 disk) I run Ububuntu in Virtual Box. That is an even more elegant solution because you can switch seemlessly between Windows and Linux (requires the "Guest Additions" which are easy to install from the vBox "Devices tab"). There is quasi no performance impact running Ubuntu or Mint in vBox.

A third solution is to run Linux from a USB stick. I do that with Fedora - but that is just for playing around.

Yes, Best way to go.

Well stated, Wolfgang. A separate HDD for Linux and Windows avoids all of these problems by keeping their relevant boot managers completely separate.

Guys,
I'm sorry I was not clear.
My problem is INSIDE Windows boot menu. I simply can't get to the repair option by pressing F8 as all the manuals state.
Leave aside GRUB, it did its job and launched Win 7. Only that the disk zone of its OS loader was damaged (don't know how, but detected by chkdsk and supposedly repaired, by the log) and I can't get the Repair menu. That's all. So, the question is how can I get that menu, because now I get the message "Please insert the installation disk and reboot"; but when I reboot I pass through GRUB and Microsoft didn't think they can share the system with other OS!
Also, I can't update to Win 7 SP1 on a dual-boot system because Windows doesn't find the partition. You still blame GRUB?
Anyway, any idea how to get that Repair menu?

Before or after removing GROB & Linux?