How to remove Worm/Autoit.AEV

My PC and pen drives and portable hard drive are infected with Worm/Autoit.AEV, how to remove them ? they keep on coming back even after AVG Anti-virus programme heals/deletes or quarantine them ?

Please download the current version of HijackThis from HERE

• Double click and run the installer.
  
• It will install to C:\Program Files\Trend Micro\HijackThis\hijackthis.exe
  
• After installing, you should get the user agreement, press accept and Hijack This will run.
  
• Select Do a system scan and save a log file. This will open a notepad file of everything Hijack This found, copy and paste it back here.