Are there any other computers on your network??

Oftentimes when I am on a network and try clicking folders/files on the network it will freeze the window sometimes because its "thinking". But its not viruses.

If you have other computers on the network, they may just be files from other computers, not necessarily anything on yours' at all.

But just to be safe, I would get a firewall and run your anti virus and spyware programs (Ad Aware and Spybot are NOT virus scanners though I do highly recommend using them frequently they are spyware programs NOT anti virus programs).

To un-network them, you can usually just delete them from the folder. Also besides a firewall turn all sharing on your computer OFF to prevent that from happening again.