A brother of a friend of mine was given a couple Apple Power Mac G4 desktop computers but they did not have the operating system software discs which she would like to have. She needs to change the passwords and so forth.

Yes it can. I have a Laptop G4 running Leopard and it runs great.

Can OS X be used in an Apple Power Mac G4 desktop computer? If not,which can be and where should I buy it?
Can OS X be used in an Apple Power Mac G4 desktop computer? If not,which can be and where should I buy it?

A brother of a friend of mine was given a couple Apple Power Mac G4 desktop computers but they did not have the operating system software discs which she would like to have. She needs to change the passwords and so forth.

Yes it can. I have a laptop G4 running Leopard and it runs great.

It depends on how many watts they are, they vary from machine to machine , but generally a power supply is about $50 machintosh being specialised could be more if you require an engineer to fit it, if it isnt still under warrenty. However, there are plenty of competent people capable of doign it if they can get the parts, Machintosh generaly only sell to licenced agents.

How much should a power supply for a macintosh G4 desktop computer cost?
How much should a power supply for a macintosh G4 desktop computer cost?

It depends on how many watts they are, they vary from machine to machine , but generally a power supply is about $50 machintosh being specialised could be more if you require an engineer to fit it, if it isnt still under warrenty. However, there are plenty of competent people capable of doign it if they can get the parts, Machintosh generaly only sell to licenced agents.