The G4 is incapable of running Windows natively, in fact, every PPC machine is. Anything that requires Intel is out of the question. I think Microsoft had some Virtual PC software... something like
this would be what you're looking for. Yes, it will be slow (only as fast as about a 600 MHz processor on the fastest iMac G4, that speeds doesn't cut it for most apps or modern OSs). Good luck, but you're better off just buying an Intel Mac.
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