iMac Transfer to new user

from my G5 iMac running Mavericks to the new iMac.

No G5 iMac (non-intel) can run Mavericks. First you need to clarify which iMac you actually have that you want to give to your grandson.

CLICKY CLICK---> http://support.apple.com/kb/HT1758 How to identify iMac models

Additionally, you cannot legally transfer any OS which was obtained at the app store - the license is yours and not transferable. The recipient would have no way of reinstalling.

You need to wipe your Mac and reinstall the original system; also give the recipient the install disks. He can then upgrade (if it is possible) by purchasing anything using his own Apple ID.

If this is yours:

http://www.everymac.com/systems/apple/imac/specs/imac-core-2-duo-2.4-20-inch-alu minum-early-2008-penryn-specs.html

it came with 10.5, so that is what you will need to reinstall using the install disks or calling Apple for replacements. If you cannot get them (as they are rather old), then you can purchase a retail copy of Snow Leopard (10.6.3) which can be used. Again, the recipient will have to upgrade using his own Apple ID after that.

Although yours is a 24", it's still an early 2008 and came with one version of Leopard (10.5.x) or another, so my suggestion in my last post is still valid.

Okay, great, you can buy the Snow leopard disk at the Apple store (unless you have one and will give that to him). He'll need 10.6.8 to access the app store for any further upgrades.