I'm thinking it could be atleast a couple of reasons.. One, your not very tech-savy and download files from unreliable sources, and you not cleaning it up thinking it'll go away.
Two, you dont have any anti-spyware/antivirus tools to clean up your computer.
Three, you never ever do defrags.
And honestly, if you ask what is defragmenting, what's anti-spyware, or what's antivirus tools you shouldnt be using a computer to begin with.
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It's really time that TGC get some night-time Moderators, it's becoming more and more annoying at nights.
WindowsXP Home(Service pack 2), Athlon XP 2400+(2.01Ghz), 1GIG Ram, Ati Radeon 9800Pro 128MB.