You really think anyone will help you get rid of Linux?!
I'm just kidding. I would use Partition Magic to do it, if you don't have that make a boot disk and use fdisk to create a new partition out of the free space. I bet Grub is still loaded in your boot record, here's how Microsoft says to restore Windows to the boot record but DON'T use this unless you don't have any important data, they have a warning on their website that it doesn't always work, so if it messes up Windows don't come complaining to me..
Use a Windows Startup disk, at the A: prompt type "fdisk /mbr"
But remember, Microsoft even says it's not guarenteed to work, and i've never tried it, i'm just telling you what they said.