New to MAC Hardware

I would like to state for the record I have little to no knowledge of MAC PCs or the OS. I apologize in advance if this is the wrong forum for this post.

I resently purchased a used Power PC G4 for my grand daughter. It has a 400 Mhz processor with 512 MB RAM. the hard drive is 10 gig with a ATI video card. The system use to have MAC OS 9.2.2 but I would like to upgrade to a newer version. I looked on APPLE website and I believe my system meets the minimum requiements for hardware for the 10.4 OS.

Question I have is this:
Is there a tool to validate the hardware is appropriate for running the newer OS? I would rather not experiment with purchasing an OS and then find out it does not work.
Thank you in advance for any assistance I may receive.

This is the best thing about macs, there will be no hardware conflicts as OSX supports all macs as far back as G3. So it will work, just pop the disc.

Mac and OS X do not have the problems that PC have finding drivers and hardware problems. OS X has all the drivers it needs to run all G3,G4,G5 and intel macs on the disc.

Macs just work.

At my parents' house, I installed OS X on their original iMac. It's a bit slow, but it's actually still quicker than it was when OS 9 was running on it. Not to mention a whole lot more stable.