"Do you have any knowledge of these software programs that are suppose to clean up and speed up your computer, such as Pitstop, Double My Speed, and so on? Do you sell any of these types of programs? If not can you recommend one?"It's a good question and a hard one to get answered because there are so many programs out there claiming to speed up your computer, fix your registry issues etc (and charge you in the process).
In the research I did, there didn't seem to be any definitive answer. Some work sometimes, and some don't. I've tried a couple myself and got almost no benefit. A better solution in my opinion is to re-install Windows on your machine (or have someone do it for you). It's drastic, but it works, as it puts your computer back into the condition in which you bought it. I do this about once a year on my Sony Vaio. You'll need the windows installation disk (unless your computer has a partition with the OS loaded onto it. You'll also need to back up all your data and then reload it and your programs.
One more point on the topic regards Apple Mac's. I've had a Mac for more than 3 years and never needed to re-build it. It still runs as fast as the day I bought it. Something to think about next time you're looking for a new computer.