I do not recommend you do one if you don't know or even if you do know what you are doing. They can mess up your machine they will sometimes remove things you need for you operating system to work properly.
This is a problem that is not real common and is usually a Windows problem the link below will take you to Norbie's World it is a free computer on line diagnostic site I occasionally go to the site and read the forums when there is a problem here I can not figure out.
You will have to register there and they will have you run some test for them and diagnose you problem. And hopefully find a solution. Could you post back here and let us know how it goes.
http://www.norbiesworld.co.uk/