BOAC, there are a range of options for deleting stubborn folders here:
Cannot delete file or folder | Windows Problem Solver
But it may be that it's being re-created by a program that starts up whilst booting. try ' configsys ' and look through the start up programs and un-tick any that are not essential, then do the same in the 'services' tab, but make a note of what you've done so you can restore them as needed