I have a couple files/folders on my PC that I "procured" from the internet ( ) which I don't want.... Trouble is the PC won't let me delete them!

I click to highlight, then hit DEL and it thinks for a few seconds, then tells me it can't delete cos the file is being used by another programme But it fucking ain't

Sometimes I have just rebooted and then deleted and it's been fine, but these two (one avi file and one folder containing a different avi file) won't delete!

Why not?