USB Key (Computing)

By Team Digit Published Date
01 - Dec - 2007
| Last Updated
01 - Dec - 2007
USB Key (Computing)

Find how you can use your USB stick to lock your computer, among other things!

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? Read on, and we’ll show you how...

Boot Lock

This trick will allow you to use your USB stick as a key to boot into Windows. If someone tries to start the computer without your USB stick, it will display boot errors. Before we begin, let us tell you that 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! Now that we have absolved ourselves of all guilt, let’s begin.

Things you need: A 64MB or larger sized USB Stick (duh!), Windows Recovery Disk (just in case).

Step 1. Unhide hidden and protected files: go to Tools > Options > View, check Show hidden files and un-check Hide protected system files.

Step 2. From the drive where Windows is installed (normally C:\), copy the files boot.ini, ntdlr and NTDETECT.COM to your USB Stick.

Step 3.  Now, we need to go into your BIOS, so restart the 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 Stick, return to the BIOS and change the First Boot device to your hard disk drive and repeat the steps above.

Step 6. Once you are logged into Windows, go to your Windows drive and rename boot.ini to boot.bak.

Step 7. 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”.

Step 8. In case Windows does not load, use your Windows Recovery Disk by following the steps mentioned at

The Other Way

For the less brave-hearted, instead of preventing Windows from booting, you can choose to just lock your computer with your USB stick.

USB System Lock

A freeware program, USB System Lock works flawlessly while locking and unlocking your computer. You can find it on this month’s Computing DVD. When you first install USB System Lock, it detects your USB stick and creates a digital key on it.

This key is used by the program to authenticate the user and log into the computer. Strangely, the program is not included in the start-up list by default. To add it there, you need to drag Agent from the USB System Lock entry under All Programs to the Startup folder in the same menu. If you happen to accidently delete the key from your USB stick while working on the protected computer you can re-assign a key using Start > Programs > USB System Lock > Key Disk Generator.

My Lock 2.0

This program takes USB-based computer locking to a whole new level. 

For Rs 400, you can lock access to not only your PC but the keyboard, CD Drive and even access to Safe Mode. You can also set a particular time for the computer to automatically lock itself. What is most interesting about the program is that you can set a passphrase so that you can use it to log into the computer even without the USB Stick plugged in. The 30-day trial of this program can be found on this month’s Computing DVD.

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