I have got an iBook G4 800 MHz with a faulty 30gb HD

I put in a windows-formatted 20gb directly from an old windows notebook.

In the install cd disk utlity won't recognise it neither will system profiler

I am 100% sure the hard drive is correctly installed

My question is. is there a chance this hard drive is incompatible with the iBook G4 or is there a way i can get it to recognize it?

Thanks in advance for any assistance.