Parallels for Windows

Running XP and am trying to learn many different types of Linux.  I would prefer not to deal with dual booting since I am in a stage of merely testing different Linux types to see which I would prefer, and as such I was wondering if any of you knew how to get a hold of Parallels for Windows.  Am I going to have to buy it or are there any alternatives (including other freeware programs that are just as good)?

You can use VMware Server for free. VMware Server will cause a few extra processes to be run on startup, slowing down Windows for a few minutes directly after boot. I haven't tried VMware Workstation, it may not have this problem. It is located at:
http://www.vmware.com/

http://www.microsoft.com/windows/products/winfamily/virtualpc/default.mspx