Problem Upgrading to XP Pro

I currently have XP Home installed, but my school has some kind of Academic Site License, and I was able to obtain a copy of XP Pro through the school. However, during the upgrade install, I was told that Diskeeper was still installed and needed to be removed first. However, there are no entries for it in Add/Remove Programs, and the folders for it in Program Files are empty.

Is there any way to figure out why it still thinks Diskeeper is installed? And is there any way to let me finish the upgrade?

check the registry.

You should just do a fresh install, not an upgrade.

is there a registry key still kicking around somewhere that's saying it's installed yet it isn't? i had a problem similar to that dealing with trial software that was uninstalled over a year ago that i needed again and that fixed the problem for me.