| Before rollover, I asked what distro you are using.
I've gotten pretty good at recovering dual-boot systems, mainly because I miss the "Configure advanced boot options" option during the Linux install.
That link I gave you yesterday works like a charm for me. Skip the stuff about the 1024 cylinder limit. The next section is what you want.
Just boot to your Windows CD, go into Recovery Console and run fixmbr. Reboot and you should be in Windows. Then, reboot to Linux rescue mode and follow the steps in the link to install grub to first sector of boot partition, copy it to a floppy or share, etc. There are links in the article that give details about the various steps.
The last time I had to go through this, I tried to use a FAT32 share instead of a floppy, but it didn't work for me. I ended up using bootpart.exe and that worked great.
Sorry if I'm oversimplifying or if this is not addressing your actual problem.
The bottom line is, Windows and GRUB play very well together. They are just picky about how it's set up.
If I can do it, I know you can. | 
