imac 27 apple id troubles

my brother bought a used iMac 27 i5 (mid 2011) ... works great went to install aperture 3 , it has iPhoto 11 on it ..pop up screen said that the iphoto liburary must be updated , clicked yes in the box and the original owners apple id pops up .. went into user groups and removed him as an admin and installed my brothers apple id but when you click update the orginal owners name pops up ... any help ..?

It's always a smart move when purchasing a used computer to wipe it clean and install the OS in your own name. I know it's tempting to keep everything the way it is because of applications that may have already been installed. However, any third party applications that require a license are licensed to the previous owner.

I recommend a clean install. That will get everything registered in your bother's name. He will of course need an Apple ID and Password.

the computer was only used twice has nothing on it .. but for some reason the guy authorized it

all done .. phoned apple support they gave download codes for the ilife .. removed all info of last owner .. this imac was never registered and apple gave my brother 130 days to decide if he wants to buy apple care ..