Help removing a virus

I clearly have a virus.  My updated anti-virus program scanned the computer and didn't find anything (Trend-Micro).  however, i can no longer get on the internet and my computer is acting crazy.  Any suggestions besides spending $300 on Geek Squad?

Can you give more detail on what is going on with the computer.

everything i do happens 10 times slower than it used to.  The screen saver comes on after 2 minutes even though it is set to 20 minutes.  every once in a while a dialog box comes up that pretends to be a windows dialog box but i can tell it's not a windows box. 

I'm hoping i can get on the internet again to download malwarebytes (i'm on my work computer now, but my home computer is the one with the problem)

if you got a thumb drive handy, download malwarebytes from work.

good idea

 

Thanks JackJaffee.  Malwarebytes solved the threats!

Cool.  That will be $300

Also if your computer start to run slow it might be fragmented. You can download a free program  "Puran Defrag"  that will do a good job to speed up things.