Mac OS reinstall after used laptop purchase?

[addj]

I recently had the opportunity to buy a PowerBook G4, and after a week - I LOVE IT, however there have been multiple users sharing the computer before myself, and I'm wondering if I can just... legally download an OS iso from anywhere and start this machine over fresh?

Thanks alot!

[hayne]

You should have received the OS X Install disks with the machine that you purchased.
Since it seems that you didn't you can either:
a) complain to the vendor (they aren't legally allowed to sell the disks separately)
OR
b) purchase the disks at retail or via eBay etc. If you get them via eBay, be sure to get the retail version of the disks, not some that came with a Mac.