Over the weekend I was trying to get delete old files, from my 600GB RAID ) config, and found that when i used the "Disk Cleanup" option I lost key OS and IE7 files. Not sure how the heck it was able to do it while they were in use, but it did.

I had to start from scratch, since running multiple OS's will cause a boot nightmare when you try to install an older OS. I have just found it easier to start from scratch then to try and fix the boot sequence.