Facebook spam message , please help me!?

[Waki]

i was in facebook then my friend sent me a message saying "hhhaahaaahaaaahahahahhhaaahahaaa
http://www.mediafire.com/?8pb5z149p1grne1 " i thought my friend was showing me an awesome link or download . so i went to the link to see the title of the download . The page didn't load anything , not even the page , but my laptop instantly downloaded something , and now , im sending all my friends this link , even through i'm not doing it!!! please help!!!

[IT-Pro]

disconnect from the internet.

Run a virus and malware scan.

Got to Start --> uninstall --> look for any weird programs here. If you question what they are, google them.
If you are using chrome, go to the wrench --> tools --> extension. Remove any thing weird from here too.