This is like writing "my computer is slow" but with no details.
For example you didn't write how you keep the malware out or what "prsence" means. That's a word I can decode.
Try Grif's advice if you don't deal with malware -> http://forums.cnet.com/5208-7813_102-0.html?messageID=3290102&tag=commProfileMain;profileBot#3290102
My laptop is dell. I use the Windows 7 system has been three months. Recently I found the computer running very slow, and prsence a lot of computer records, I want to clear them, but could not find suitable software for Windows 7 before, or else with some of the time-consuming too long, or else is unstable, and now computer slower and slower, I do not know how to do, who can help me