Help me Please!

Hey All,
I have an issue going on with my computer. I am pretty computer savy, but recently had a file come up as corrupted and unable to repair or delete with Avast. I have the free version, which may be the problem, but I was hoping someone much smarter than I could help me out.
I have a trojan horse virus with this info c:\windows\system32\comdlg32k.dll\[UPX].
I did stop my system restore and attempted to restart the computer in a safe mode and allow avast to run and detect. I had the options of deleting, repairing, and so on. None worked other than Ignore, which obviously doesn't solve the problem.
Any info or advice would be greatly appreciated. I just had my computer completely wiped no more than 3 weeks ago and it cost me $275 to save everything I had on the hard drive, wipe the comp clean, and restore my saved files. I really don't want to take it in again!! Please help!!

Thanks!

 

My computer says that it should not be run with the virus on it. Will it be safe to run it through this program? I actually don't have internet to it right now, but could if need be. Just let me know if running the computer will cause problems?