[NCLUG] Starup problem

[OWEN BLACKLOCK]

As a newbie to linux, I tried to install a linux distro to an external USB hard drive connected to my HP laptop.  It seemed to go as planned at first but somehow my Windows XP OS stopped booting up on startup and opening with GRUB instead.  GRUB appears with a blinking command like curser but nothing can be typed in.  Linux distros can be accessed through the CD/DVD drive and I have tried to use Knoppix to solve this problem but with no success so far (probably because I don't know what I'm doing).  My goal is to get my Windows XP back as the startup and probably try to dual boot Windows XP and a Linux distro on the primary hard drive.  Hope there is a fairly simple solution I just haven't learned.
I at least know I haven't lost my laptop info because I can see it when I run a live linux disro but just can't get there thru the opening boot up process.  Any help from anyone would be greatly appreciated.

Owen