Thanks for replying David.
I will try your suggested steps, however a new problem has shown up:
I was working with Dell, who suggested I re-install the operating system. I did, and now the Eraser menu will not let me choose the drive clean as an option. C cleaner wipe, instead of starting normally now does a prescan, stops at 45-47 % eventually finishes to 100% and starts. It shows completed when I reach 45-47% - very suspect.
Dell XPS windows 7, ESET antivirus, c cleaner, Super anti spyware, installed. (prior to this I had spyblaster and spybot installed, and had Microsoft Security Essentials.)
I'll try your steps and get back to you.