I got this from UbuntuForums.org, thanks strydermed
If you are stuck in a dual boot with Ubuntu/VIsta or triple boot with Ubuntu/Vista/XP and want to remove Linux without affecting XP and /or Vista , there are many options..
If u have a Vista DVD, just boot off it and use the recovery console. Type bootrec /fixmbr
That's it you are done.
If you don't have Vista DVD, then there are a few options.
If you have deleted your Ubuntu partition from Windows you might that your system refuses to boot. Download Super Grub Disk and burn it to a cdrom, you can restore Windows after booting from that.
If you can boot into Vista then, there is a easy way. Just follow the steps below:
1. Download MBRFIX.EXE from http://www.sysint.no/en/Download.aspx
2. Put it in your C or D drive. It does not matter where. Now right click on it and select security tab. Make it "Run as Administrator"
3. Type cmd in vista search box in start menu and right click it and select run Run as Administrator.
4. In the command prompt go the directory where u have MBRFIX and now type MbrFix /drive 0 fixmbr /vista /yes . This wont work without administrator permissions. Replace 0 with the number of ur drive. Just leave it if u have only one hard disk
That's it reboot and Vista boot manager will be back in place of Grub. Now you can go into Diskmanager and format Linux partitions and reclaim the space