Packed.Generic.200 in system file and can't delete!

I have run the Norton antivirus many times and had to manually remove the viruses because norton doesnt delete any of them. However, there are a few that I cant delete because they are system files...I think. Please help! This virus just wont go away!

 

 

This is the file path

C:\WINDOWS\temp\1777328.tmp

 

I'm sure the virus has generated more by now, but if I know how to get rid of this one, I hopefully can deal with the others.