>>3
I had a folder named '4chan' within another folder of pictures. I was reducing some of the pics in size and saving them to the 4chan folder so I could post them in /p/ without getting the image too big error (used IrfanView to reduce & save, in case that matters). Anyhow, when I was done posting, I went to delete the 4chan folder, it gave me the in use error. I used the cmd promt to del the files within the folder, but still couldn't delete the folder itself.
Funny thing, though, I simply renamed the folder from 4chan to 'asdf' and then deleted it without any problems.