I was copying over 140 GB of my User / My Documents from a Win XP Acronis backup into a benign folder in My Documents on Win 7. Half way through this multi-hour transfer, there's a 20 second power outage that disrupts the transfer completely. Now I'm trying to delete everything I transferred onto the Win 7 machine so I can start that job over. There's obviously way too many subfolders going on. I "Take Ownership" of the top folders, my laptop makes occasional beeping noises while the DOS screen goes by super fast with permission changes; I can only assume beeps means changing the permission failed somewhere. So I am stuck going though hundreds of folders and files one at a time trying to see if it's deleteable. Some are horrendously stubborn and nothing can make them delete.
Geez, I'm just trying to clear out a total mess and I can't because I've been refused permission. This is awful. One file even told me it couldn't delete because Windows was protecting my system from it, it's M$ blacklisted, the file is really old too.
doubled up OS disaster 
