Question : Can't ping new SBS Install

I wanted to replace an old SBS 2003 with a new one.   I had an old, unused copy of SBS 3003 premium.  I installed SBS with updates, then ISA server (2000) with its updates
I gave the new server the same IP and name as the old.  I plugged in.  I struggled to configure ISA server, gave up, and decided to uninstall it and the updates.  (I had hoped to get ISA 2004, but no longer available as part of updates).

Now I can't even ping the new server through the clients, either by name or IP address. The new server can ping itself.

I have
Restarted
Rerun
change IP address wizard
Disabled second NIC
Run "Change IP Address" wizard with same IP address
Rerun CEICW
Entered without difficulties:
IPconfig /flushdns
IPconfig /registerdns
net stop netlogon
net start netlogon

Not sure what to do next.  Many thanks for any assistance you can offer.

Answer : Can't ping new SBS Install

Actually I was thinking isa 2004+, I'm not sure what the firewall service name is called in isa2000.