Problems booting with 3 copies of XP - 2 corrupted

Hi. Ok this is a bit complicated. I wanted to install another copy of XP onto my external hard drive just in case the one on the laptop got corrupted or infected. I used the USB 2.0 port to connect the hard drive to my Inspiron 6000. The install went fine until I got a blue screen saying the process was stopped to prevent damage to the computer. It also told me to check the drive using ChkDisk. So being a retard, I decided to just format the drive and try again. Well it didn't work the second time and now I have THREE copies of XP on the OS choosing screen. Problem is, it keeps automatically selecting one of the copies that is corrupted so now everytime I want to just use my laptop I have to manually press F8 and choose the working copy. Is there any way to remove the two corrupted copies from the OS choice screen?