First I bought RegCure, and Pareto PC came with it. As others have indicated, RegCure is useless. Pareto PC is supposed to clean up unnecessary files. When I first used it, I found there was no relation between the files it found and what was actually in the folders involved. I could empty a folder and yet Pareto PC claimed there were many files in it. Also when I used Pareto PC repeatedly, it would still show files that were not deleted, and sometimes even increased the number of files from the previous deletion attempt.
More recently, Pareto PC freezes the computer when it is halfway finished (according to the bar) so it cannot do anything. To add insult to injury, the online ad claimed that there was a reduction of ten dollars, but I was billed the full price anyway. What a rip-off? I strongly advise against buying anything from ParetoLogic; it is bad news.