I let it do it's thing, so to speak, and it puts old windows files in windows.old or w/e.... Should I reformat the drive, in case I had some files on there that are infected? I noticed that some of my settings, well - my icons, for certain folders, were still intact, like one of my non C drive folders on other drives had my custom icons I picked for them. Just how much stuff/settings is left behind with installing windows this way? I guess I should just reformat. I don't think I had any viruses but who knows, might as well start fresh...kind of annoying though to eat up another 2 hours installing it again. BTW I used the bios mod and it validates Woo!
When in doubt, reformat. Easy to do and much lesser headaches (of course, installing softwares and customisation) can be a pain, but worth it. Be sure to (a) back up your non-OS data and docs (b) make a system image immediately after activated OS and updates install.
if u want to properly remove windows.old folder, use disk clean up, select the C drive when it scans it and gives u the options to select what you want to delete, look at the bottom of that dialogue box u should see "clean system files" clcik that rescan your C drive and then in the options u will see, Previous Windows installation, tick it and it will delet the windows old folder and everything in it