To remove viruses of USB port (windows creates shortcut while plugging in pendrive), which cannot be removed by antivirus-softwares. .
Try this...its really works.
>>Open Device Manager (in all windows)
>>Expand "Universal Serial Bus Controller"
>>Uninstall all components under "Universal Serial Bus Controller"
>>Restart computer and let it be idle for 3-5 minutes (windows will automatically reinstall all hardware which will free of viruses).