help to remove win 32:luder-f virus/worm

Viruses and worms
1

Hello members,
My friend accidently clicked the file with extension .pif then we scan the system as usually by installing my favourite antivirus AVAST. When I scanned Flash.exe file it showed that Win32:Luder-F Virus/Worm iNow how to remove that virus when i clicked to repair iit is telling that file cannot be reapired.
Now what I must do. Format the whole PC or any other way to remove that virus.
please help me .

                                                                                                           Regards,
                                                                                               Bharath Radhe Krishna.
2

Do a boot-time scan. Quarantine everything you find. Try another on demand scanner after that to make sure you are clean [AVG AntiSpyware (http://www.ewido.net/en/download/), mwav (http://www.mwti.net/products/mwav/mwav.asp), etc]