The problem is, I think some of my games do require XP. So would it not be "safe" to have XP, or are you saying it would just eat a lot of memory?

Also, I have a basic understanding of how partitioning works - it makes multiple virtual drives on a single disk - but I don't understand the interactions between the files and applications on different sides of the partition. Does it matter which side I keep my PC programs on? Will they have to be in the same drive with the Windows OS or can I just use Windows to run them from wherever without any ill effects?