I tried to dual boot my computer with Gparted and now it won't start up.

Hi,
I tried to dual boot my computer (XP/Heron)
using GParted, a disk partitioner. I realized
after I had installed Ubuntu 8.04 that I had
allotted too much disk drive space to the
partition that Ubuntu was installed on and
to fix it, I thought I could just run GParted
again and resize my XP disk to fill up my
entire HD (thus removing Ubuntu and
allowing me to reinstall it with the correct
disk partition space). But then when I tried
to reboot- my computer give me the message-
"GRUB Loading stage1.5.

GRUB loading, please wait...
Error 22"

Now I can't do anything.

Please help!