Why is my computer running so slow?

Some quick tips. Run an antispyware program. Microsoft has a free one, it is adequate but not as comprehensive as some of the commercial ones. Run antivirus software Norton or McCaffee are both good choices. Do your system maintenance tasks, defrag your hard drive, empty the recycle bin and your internet cache. There are many other things that can be done but those basics should keep you fairly clean and running at a decent clip, assuming your machine ran faster to begin with.