Help removing a Quarantined Trojan Horse

I continue to get a pop-up stating my Symantec AntiVirus has quarantined a Trojan Horse, Filename - SaB0p62m.dll - and have tried to delete the Trojan Horse (right click on the message and select "delete from system "), but continue to periodically get the pop-up. The original location is C:\WINDOWS\system32\ . I have done a full virus scan and cleaned my system, but it hasn't helped.

I'm also getting a voice over message that says, "Congratulations, you have been selected to receive a $1000 Wal-Mart gift card" but there is no visible pop-up. While typing this message, I also started getting various sound effects (sounded like repair work being done), again with no visible pop-ups. I'm not sure if this is associated with the Trojan Horse because they happen at different times.

Can someone help me get rid of the Trojan Horse pop-up and the voice over and sounds?

smorel1313