Newbie installing XP Pro with Parallels 5

I have an iMac which we just upgraded to Snow Leopard from Tiger. I attempted to load my Win XP Pro onto boot camp only to discover I couldn't because the version is too old. So a friend suggested Parallels. So before I go out and buy it I am using the demo to make sure I can get it to work.
I installed Parallels 5 without a problem.
I began installing XP Pro and it went through to about 9 minutes left and froze.

Now, I cannot Remove it because Remove is grayed out. When I try to start it, the setup restarts at the beginning and I am told it can't find the ASMS file which is where it is looking for it.

I have tried installing the Parallel Tools which seem to be in my Applications but are still being identified as uninstalled on the Window window.

So, if I try a fresh install will it install over top and wipe out the one I have already done. If not, how do I delete the faulty one?

Thanks,
Mary