I have p5 on my data drive which is a slaved drive. Recently, I installed a new and larger data drive and formatted it then copied all my data from the old one from within windows (including my P5 directory). Then I ditched the old data drive. Worked just fine. P5 runs like normal. However, if you are swapping your C drive, then there are registry issues. you can try it but don't format your old drive until you know its working.