how to change administrator and network passwords on 2nd hand imac imac computer computer
see above
iMac, not sure
see above
iMac, not sure
What iMac is it, and running what version of OS X?
Changing or resetting an account password via GUI:
Resetting a user's password
Resetting the original administrator account password
Here is how to change the password from the install dvd/cd
How to run reset password from your startup DVD.
Restore dvd's 10.4 & 10.5 available from Apple by calling 800-767-2775 on January 20, 2013.
https://discussions.apple.com/thread/4720126?tstart=0
Here is how to find out what version of Mac OS you are running:
Click on the blue apple in the upper left hand of the screen.
click on this icon
Click on the first line, "About This Mac"
Most of these are numbers & that's what we want.
What version & Processor do you have?
how to change administrator and network passwords on 2nd hand imac imac computer computer