I bought Registry Booster in 2/11. It was working for a while but after April 2011 update empty white window comes out and stays frozen. 9 emails and useless answers from techsupport plus waist of my time. I requested a working product or refund 5 times. Instead I got a final blurb that my antivirus may be at fault and a link to old version.
Please, don't pay them! It is as bad as it comes. I keep all their emails for any legal action later.
Mike Gleizer.