freezing g4 ibook

Have been given an ibook and was told it froze when first loaded, so am trying to figure out if its the ram or the hard drive.
So decided to reinstall tiger and it gets as far as either the choose language or within 2 mins of starting reinstall.
Its a 30gb oldish 12 inch ibook with a 1gb stick installed one make i have never heard of before Trump Disco816D DDR 1GB -333 mhz SO Dimm

I don't want to buy both ram and hard drive together so what do you guys suggest.

I have a diagnostic disc for the ibook but when i try to use it, it says not for my model (it didn't come with the ibook, i just had it from a previous model)

It's hard to say with a machine that old. But one thing is for sure and that is you're going to need the correct disk or a retail disk to do some trouble shooting and possibly reinstall the OS.

The freezing could be the hard drive or memory. I would probably change the hard drive first.