1. This is to crack the actual computers admin, NOT the server admin. (This may not sound to useful but, you will be surprised how nice it is to have full access to any non-server file, like command prompt)
First, you will need a cd to burn ophcrack to, download and burn the image from here
Second, bring the cd to school or your place of business
Third, change the boot sequence by restarting a computer with ophcrack in the drive and hit F2... from there change the boot sequence to boot from CD as primary.
Four, save and exit and it should start from the CD...
Five, choose graphical interface and just wait for linux to load and for the SAM file to begin being cracked. (Idk how long it will take, but it took five minutes for me the first time
Six, remember the user name and password, and you are done... You now have the administrators password for that computer... which for later can help you sneak around, delete anti virus, and even use programs like PsTools to remotely execute programs...