one of the most useful windows utilities is Ccleaner
http://www.piriform.com/ccleaner
there are other software of course, but this is essential since windows is so slow when compared to linux, I left windows for good, it sucks, i switched to linux mint, i wish i did that long time ago. no anti virus, no need for software to speed up my pc, no crap, linux is heaven in the computers world :)