Virus protection and such

Hi all I am in need of protection from spyware virus and such but am unsure of what product to get I had anti-vir and got a trojan so I need to know what i need to protect my puter. Please any help would be nice Thanks so much Sabrena

 

O.k. Thank you .I did every thing you said I down loaded Avast antivirus,Zonelabs fire wall spybot search and destroy and spywear blast and ccleaner and I ran avast and found no problems have my firewall up and spywear blast up and ran spybot search and destroy but I still have a thing coming up on the spybot it says Windowssecuritycenter.firewalldisablenotify I am not sure what is means or what I ned to do I will select fix problem and then rerun the program and it comes back again.

 

Thank you so much for your help this is a wonderful place