Help!: Where to get good antivirus?

Hello! 

I've got an virus or spyware in my PC 

Now my computer is really slow and shows various pop-ups and stuff, what to do and how to get rid of them?

I really would like to get some help because my PC is full of very important family pictures and stuff.

Viruse name is TJ.Worm32.Heurestic
 

Please help!