Some sort of spyware?

I need some help from some people. A friend of mine was looking for some music that he could not find, so he went to google and he went to a bunch of sites there. I wasnt in my room while he was searching but he went to a site that did put something on my computer. He doesnt know what site and I dont know what it is that is playing with my computer. What it does is change my homepage in explorer and make my history a bunch of porn sites. Also, I cant open windows media player anymore, and everytime I try, it does the same thing that restarting did, and messes with explorer. Anyone know how to get rid of it? I tried adaware and a virus scan and got nothing. Help please.

Shut down all you apps you have running and check your task manager to see what else is runnng. Check online to see if any of them are spyware of viruses. Post a pic of task manager if you want more help on wants not supposed to be there.

Search for files created around the time when he was on the internet and look for programs of appropriate size, look through add/remove programs, check your internet options, look through the programs in the startup folders, check what programs are being run at startup (msconfig if you have XP), check what services are running.

Mentioning attempts at copyright violations and file sharing programs like Kazaa are actually against forum rules, though many people aren't aware of this. Since it's not really essential to solving your problem, can you remove those references so a Mod doesn't have to?