I have the same problem here (ME too). The problem started when I got my ADSL connection and after I installed a firewall (Norton Internet Security). Before that everything was ok.
What I'm now doing is: not using my ADSL connection at the same time, and even restart my machine after the ADSL logout (necessary). Besides that turning off Internet Security. It's far from satisfactory but at least it works for me now. I'll have to explore this further because I need local Zope and the ADSL connection at the same time.
Henry, thanks for saying that. my friend was also running 'black ice' ? personal firewall and an abrupt reboot would occur on Zope startup. I was helping my friend remotely - and he isnt the most technical fellow. I believe he had 'disabled' the firewall program, but he may not have rebooted. A Norton program was running as well. Again, I didnt have time to debug the problem. He installed Windows 2000 Professional and the problems went away. I believe he is still running Black Ice on his new Win2k setup with no problems. thanks, ~runyaga