I don't buy into those. I used to work at OfficeMax some time ago, and if you had an issue with your computer, we would hook it up and run our own software that's similar. It would tell you if there was a virus detected, or if there were files that could be deleted etc. Honestly, the whole thing was a crock, and still is. Most of the time when it says there are files to delete, it's talking about temp files, or files sitting in your download folder. Even your recycle bin, if it has stuff in it, will trigger the unnecessary files. If you take it in to them, or BestBuy, I can almost guarantee that it will say you need to do/remove something!
If you're worried about bloat from having surfed and downloaded too many things, I would instead suggest you save all your data to an external source, format your drive, and do a clean install of your OS and programs. Yes it can detect some bloatware, and maybe let you know if there's a virus on your system, but there are other more reliable means of checking for the really bad stuff.