Has someone suggested to you that installing a second Anti-virus program would be a good idea? I see you have AntiVir installed now as well. This really isn't a good idea and will cause more problems and instability within your machine. I suggest you uninstall it immediately unless Norton has expired in which case Norton should go.
Open notepad (Start > Run and type notepad) and copy/paste the text in the code box below into it:
Code:
File::
C:\WINDOWS\system32\mljjk.dll
C:\DOCUME~1\ALLUSE~1\APPLIC~1\nebyzkdm.exe
C:\WINDOWS\system32\winwim32.dll
Registry::
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"nebyzkdm.exe"=-
Save this as ComboFix-Do.txt
Refering to the picture above, drag ComboFix-Do.txt into ComboFix.exe
Run ComboFix again and post the resultant log file please with a fresh HJT log.