[cba191]

the $windows.~BT and $windows.~ws folders.

[NeoDerGrosse]

I tried it, but I can't delete it. I guess I have to use a special program to get rid of it. But I didn't yet have the courage to do it.

[Krazeh]

I had the $windows.~ws folder after updating from windows 8. Was able to delete it and haven't had any issues.

[Firipu]

Just use the disk cleanup utility. It'll get rid of old windows installations and all that stuff. It'll give you a warning that you won't be able to return to your previous OS though, but who cares :p

[NeoDerGrosse]

Ok, I got that wrong. I still do have Win8 and problems with updating. I wanted to delete it because I guess the files are corupted.