I've been having problems with a used Samsung 12.1" notebook I bought. It not very powerful, but was running slower than it should be - definately noticably slower than my netbooks. I initially thought it was due to overheating. However after blowing out the air vents with compressed air, the laptop was running cooler but not faster. I had tried all I could - short of doing a clean install of Windows 7 to increase the speed, but with little effect. Even running the pro version of Advanced SystemCare did little to help. Since I have been thiking about selling the laptop (cheaply due to speed issues) I decided to install CCleaner and do a clean with the default settings (usually the first thing I do after installing CCleaner is to deslect all options to clean mru/history data so that junk file are the only things cleaned, I don't even clean cookies). Now my laptop is running a lot better. While I had run disk cleanups with several programs, I had always selected to not clean any MRU/history data. This is something I never ever clean as don't want it removed. For example I want my web browsers to know remember my browsing history so that I can go to previously visited sites more quickly, i.e. I start typing in a url and autocomplete will finish it for me. Also another example I like that when I go Start/Run it remebers previous commands entered. I was really surprised that cleaning the mru/history data made such a difference in speed - I did not think it would affect performance. Now my laptop is running as it should.