I have a white MacBook from a friend who cannot remember her password. She is running 10.6.4. When I boot off of four different OS DVD's ranging from Leopard to Snow Leopard the final result is a screen whose message is: You need to restart your computer. Hold down the Power button until it turs off, then press the Power button again. I can boot to the desktop without any problem and use the computer. It is running great. The computer recognizes the DVD's as OS discs. It would be nice to change her password. Any suggestions on why I keep on getting the above message would be appreciated.