help! i have encountered a trojan horse and i get the message:

Trojan Horse Downloader.Turown A
C:\System Volume Information\_restore{F6ACA4CE-D4AB-465-A4F2-6A4B0A1E5CBC}\RP210\A0039298.exe

the message tells me to run avg to get rid of it...but when i do, the scan says there is nothing found! how do i get rid of this thing????

thanks!