I see you have 3 separate threads for the same problem. Please STOP creating any new threads.
The forum is extremely busy and so are the helpers.Make sure you follow all directions outlined as perliminaries herehttp://www.bleepingcomputer.com/forums/t/34773/preparation-guide-for-use-before-using-malware-removal-tools-and-requesting-help/
Do as much of them as you can.
The message you are getting
"Application cannot be executed. the file dds.scr is infected. Do you want to activate you antivirus software now?"
is from the malware rogue.
Try this to at least get the message box closed. Press and hold ALT key and then press the F4 key on your keyboard.
BTW, do NOT run Combofix on your own. That tool is not to be used lightly and certainly not without guided expert help.
P.S. ALWAYS state your Windows version/edition when starting a thread topic !!!
Edited by Maurice Naggar, 30 April 2010 - 12:20 PM.