Please Help! What do I do?

I have Synmantec antivirus endpoint protection and somehow a vrius got into my computer and disabled it has been replaced by this fake antivirus software called PC antispyware 2010. I know its fake because as soon as I went to this one website, my computer shut down and when i turned it back on, the spyware was installed. I tried running my antivirus scanner but it has disabled that too! what should I do? Please help.

You should reformat your pc and buy an original anti-spyware

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