Speed up your pc

When I was in the Philippines I had a hard time speeding up my computer. When the person checked it out he said it has a lot of virus and that it needs to do some cleaning. At the time I don't have any knowledge of how to do it so I did let this person checked my computer but it turns out it's still the same. Now while I was searching over the internet there are some helpful sites that is willing to help you speed up your computer and here are the three that I find realistic to me.

1. win 7 internet security 2011

2. windows security alert

3. relevant knowledge