Deleting incomplete installs of XP?

I have not used Parallels yet, but several months ago I attempted to install Windows XP. The disc looked to be in good shape, with only slight scratch/buff marks on the disc. The install went for about 30-40 mins then froze. I gave up and didn't attempt it again. I am on my way to the store to buy a copy of the Win 7 family bundle and would like to install in Parallels. How could I delete the incomplete install and any other useless files that are there from the failed XP install? I don't see the files anywhere in the computer, but I just want to be sure I am starting from a clean system. Also, should Win 7 install okay in the current version of Parallels that I have. I just downloaded it from MacUpdate about 6 months ago, tops. It is Parallels 5.0.9344. Am I going to need version 6 for Win 7? I don't want to pay any extra money if I don't need to. Thanks!

 

Good thing I called Best Buy before I drove out there. Apparently I need the whole version ($200) opposed to the family bundle ($150 which is just an update it turns out) to install into Parallels. I am currently working on getting a better version of the XP disc. At any rate, I still want to delete this incomplete install if anyone has any helpful info for me. Thanks!