There is and your going to love it

Get your XP cd out and log into its recovery console.
http://support.microsoft.com/kb/314058

Use the recovery console to repair the MBR, PBR,NTLDR & Boot.ini by typing the following commands

Copy e:\NTLDR C:
BOOTCFG /REBUILD
Fixmbr
Fixboot

Restart your machine and make sure it boots into XP. when it does use xp explorer to delete the windows directory on the other drive along with the boot folder and users folder..job done.

The above commands asume you only use default drive letters & only have 2 Hard Drives.

Let me know if you get this done.

how big are ur two hard drives?
cause u could try and move all the stuff u want to keep to the XP hd and then format the vista one?
could work but may take a while!

One drive is 80gb, and the other is 40gb.
By the way, can you possibly give me a list of folders that contain the windows vista data, so I know which ones to delete?

Thank you all so much for your help!

I forgot to mention that I do not have the Windows CD, because the manufacturer (Dell) "conveniently" did not include it with the computer. But I believe they gave me some software on a CD that does just what you mentioned.

Folders in Vista

?:\Windows -windows vista duh!
?:\Boot -Bootfiles
?:\Users -documents, pictures etc...
?:\Program Files -All installed Programs.
?:\Bootmgr - should be deleted as part of windows vista boot structure.