Hummm... I will have to forward computer questions to DH! Both Crazy Machines and Chemicus say Win98/ME/2000P. But I can't find the original box for Physicus. We have a newer Mac for DH and me (3 years old), and an older Mac (7 years old) for DS. I'll ask DH, the computer geek, this afternoon or evening and post more info later.

Mom to DS12 and DD3