All you need is a entry in grub to boot you windows partition. If your windows partition is still there and you didn't over write it then I will assume its on sda1 so in that case you need to do this:
open a terminal
nano /boot/grub/grub.conf
add this to the bottom
title Windows
rootnoverify (hd0,0)
makeactive
chainloader +1
There is no uninstaller for linux



