Thats really a nice trick of locking PC with a Pen drive. Instead of locking/unlocking your computer by using the traditional way that you said, you can easily do it with the help of PREDATOR. It locks your PC when you are away, even if your Windows session is still opened. It is really a secure way for you to lock/unlock your computer by using a regular USB thumb drive when it is removed/inserted to the drive.It uses a regular USB flash drive as an access control device, and works as follows:
Insert the USB drive
Run PREDATOR (autostart with Windows is possible)
Do your work...
when you're away from your PC, you simply remove the USB drive:
once it is removed, the keyboard and mouse are disabled and the screen darkens
when you return back to your PC, you put the USB flash drive in place:
keyboard and mouse are immediately released, and the display is restored.
To start monitoring your PC:-
Insert your key
Run the software via the Start Menu / Programs / Predator item or via the PREDATOR icon on the Desktop
Make sure that the padlock icon flashes in the taskbar
How to lock my PC with USB pen drive :
You need to insert the USB drive and start Predator. It will show anicon in taskbar. When you need to leave away for sometime look at the padlock icon in the taskbar: if it is red, wait. If it is blinking, remove the key. The desktop will be locked in a few moments, depending on the settings you have chosen. When you are back insert the key. The desktop will be unlocked in less than a second.