How to lock your computers using USB

If you want to protect your computer against others, then wouldn't it be cool if you could lock your computer by just removing your USB stick from it??

Boot Lock

This trick will allow you to use your USB stick as a key to boot into windows. Anybody who tries to start the computer without the USB stick will be displayed with boot errors. Performing this will be at your own risk..

Things that you need.
A 64 MB or larger sized USB disk and a windows recovery disk(just in case you require it)

Just follow the steps given below.

Step 1:

Unhide hidden and protected files. If you are unaware on how to do that
Goto Tools->Options->View, check show hidden files and uncheck hide protected system files.

Step 2:

From the drive where windows is installed, copy the files boot.ini.ntdlr and NTDETECT.COM to your USB stick.

Step 3:

Now we need to go to your BIOS. So restart your computer and keep jabbing F8 as soon as the computer starts.

Step 4:

Once in the BIOS, enable USB Drive as the first boot device. You might have to enable USB Legacy Support on older BIOSes.

Step 5:

Restart your computer, if all goes well you should be able to log into Windows. If not then unplug the USB disk and return to the BIOS and change the first boot device to your hard drive and repeat the steps above.

Step 6:

Once you are into Windows, goto your Windows drive and rename boot.ini to boot.bak.

Step 7:

To check if you have setup everything correctly, eject your USB disk and reboot your computer. You should get error messages on the screen such as "Invalid Boot.ini" or "Windows could not start".

Step 8:

In case your Windows does not start use your Windows recovery disk to start your windows.