The "you may be the victim of software counterfeiting"
warnings are the result of your not "Activating" windows, which is to say entering the product code either installation OR later if your particular installation disc allows you to enter it later.
It is often required that they let you defer "activation" because until you've installed important stuff like network drivers you can't activate.... windows must "phone home" during the activation...
Though it should be noted that with some computers from larger manufacturers when using the factory "reinstallation" discs this process is either automatic or bypassed because of a prior agreement between Microsoft and the specific manufacturer.
When reinstalling the OS on a Dell in particular you will usually not be asked to "Activate" windows for 2000, XP or Most Vista versions.
I can't recall the last time a Dell asked me for a CoA during or after
reinstallation.... remember you DO have a "license" it was part of the purchase price for the original computer.
HP or Compaq will usually give you 15-30 days to "Activate"
30days on most XP versions 15days on Vista.
But in any case if you want to "cripple" a windows installation you can go to "My Computer" and open drive C, go to the root directory and delete ALL the files there then reboot the computer... windows will not come up again...
Simply deleting "NTDLR" will accomplish that....
Frankly I'd do what someone suggested above... boot from CD with a windows installation disc in the drive....
ANY windows NT/2000/XP/Vista/7 installation disc
and use the installer to format the disc and when it finishes it'll ask you which partition you want the OS installed on... at that point pull the power cable. (abrubt powerdown doesn't hurt a thing while out of windows)
When installing an operating system on a used drive ALWAYS take the option to format the drive or partition where you are installing windows... (or whatever Operating system strikes your fancy...)
Without formatting before installation (even a "quick" format) Windows will NOT delete the old operating system files, directories and applications from the drive, but they will no longer work and they will make defragmenting the drive nearly impossible...
Not to mention that the "dead" OS being on the drive makes running the system like trying to run a marathon with your DEAD conjoined twin still attached to your body.
You may finish the marathon, but you ain't gonna win.
If you are an IT guy with a nasty streak and someone has recently annoyed you....