How To Lock Your Computer With USB Drive

How To Lock Your Computer With USB Drive
Tired of people starting your computer when you are not around and messing up custom settings? Wouldn’t it be cool if you could lock your computer by just removing your USB stick from it? I’ll show you how you can use your USB stick, Flash Drive or Pen Drive what ever you call it to lock your computer, among other things…

Boot Lock
This trick will allow you to use your USB to BOOT into Windows. If someone tries to start the computer without your USB stick, it will display boot errors. Before begin, you playing with the BIOS and boot files of your computer may result in you not being able to boot into your Windows partition; so continue at your own risk! Things you need: A 64MB or larger sized USB Stick, Windows Recovery Disk (just in case).

 Unhide hidden and protected files : Go to Tools > Options > View, check Show hidden files and un-check Hide protected system files.

From the drive where Windows is installed (normally C:\), copy the files boot.ini, ntdlr and NTDETECT.COM to your USB Stick.
Now, we need to go into your BIOS, so restart the computer and keep jabbing [F8] as soon as the computer starts.
Once in the BIOS, enable USB Drive as the first boot device. You might have to enable USB Legacy  Support on older BIOSes.
Restart your computer, if all goes well, you should be able to log into Windows. If not, then unplug the USB Stick, return to the BIOS and change the First Boot device to your hard disk drive and repeat the steps above.
Once you are logged into Windows, go to your Windows drive and rename boot.ini to boot.bak.
To check if you have setup everything correctly, eject your USB stick and reboot the computer. You should get error messages on the screen such as Invalid Boot.ini” or “Windows could not start”.