Help removing trojan.gen, trojan.gen.2, and trojan.zeroaccess please

Somehow this got on my machine, and keeps popping up over and over and over.  Before I found this forum, I tired to fix with symantec antivirus, malwarebytes, and search&destroy, nothing seemed to work.  Please help me

 

Thanks in advance

 

OS is Windows XP 32 bit

I have a flash drive

 

(currently on another machine because the amount of popups on the infected machine is overwhelming)