I recently worked on a computer issue for family we all know how that is.... where they purchased a laptop and they did not change the admin password. I did crack this and fixed it but realized how vulnerable my network at work was to this kind of attack. basically I used a linux type disk to do this I won't go into details so that I don't give any information or how to's.but I wanted to know how can I prevent people from doing this to my laptops or desktops. basically how do I prevent programs from taking the hash and deciphering the password . I don't want to prevent all boot disk as I may need them for recovery myself. I wasn't worried as much when these programs just reset the admin password because I would be able to tell but when nothing changes and they just learn the password that can be very dangerous. any advice on this is greatly appreciated.