You have a few options...
BEFORE anything... Because of my 0 reputation, some links have hhttp:// instead of http://. You must remove the first (or second hehe) 'h'.
The others are right, the "rm -rf" did screw your linux install... You may have even lost your /home directory if it was mounted at the same time...
Use the Non-Commercial/Free EasyBCD Editor - hhttp://neosmart.net/dl.php?id=1
Use the following howto to restore the bootmanager (thanks Google :P)
Restore Boot Manager - hhttp ://neosmart.net/wiki/display/EBCD/Recovering+the+Windows+Bootloader+from+the+DVD
Use the windows CD to load up in rescue mode, then do "fixboot" or "fix-boot" or "fixmbr" (I forget which one, I think its fixmbr) then reboot.
Reinstall linux, then use grub to boot windows. After booting windows, try the above commands ("fixboot" or "fix-boot" or "fixmbr"). After you do that, reboot to make sure it shows windows bootloader. If it shows only the windows bootloader, then use a windows partition manager to blow the linux partition.
Option 5: (probably your best option)
Use a bootloader rescue disk. If this doesn't work, Google for "Bootloader Rescue"
- SuperGrubDisk - hhttp://www.supergrubdisk.org/ (a rescue disk for grub)
After, just use the windows command line and "fixboot" or "fix-boot" or "fixmbr" (whichever it is... Again I think its fixmbr)
Once back in windows...
I would advise installing a third-party boot manager, such as Acronis OS Selector or another open-source one. If you need, Google "Graphical Bootloader". I like Acronis OS Selector as it is point and click graphical bootloader. And NO I do not work for Acronis, or get any revenue or % of sales.
Good Luck, and accept answer if you manage to fix it with any of my methods :)