iMac G5 not able to install OSX

Hi,

So i recently bought an Imac G5 from a market, because i like that kinda stuff. The seller told me there was no hard drive in it, so i had to install my own and install Mac OS on it myself. I thought that that could not be that hard.

I had just taken a Hard drive out of a Dead laptop (The hard drive still worked, i tested it) and installed it into the Mac (I did not format the Hard drive yet, there are still Windows files on it, i dont know if that is the problem.). But when i booted it up with the drive in it, it would still give me the same flashing Questionmark and Mac logo.

I tried installing Mac OS X onto it, not with an official install Disk, but with my own. The only thing is, i tried like 7 different disks and files, CD and DVD, and it didnt work a single time. The diskdrive would try to read it, make some weird sounds, and then automatically eject it after a while. (With the last 2 attempts a grey screen would stay on while the diskdrive was trying to read the disk) Also nothing shows up in the boot options menu. I Also tried a bootable USB stick, but that also didnt show up. (I have used TransMac for the USB stick and some of the DVD attempts.)

I've tried to install Mac OS 10.0 and 10.3 .

Does anyone know whats up?