Install to SQL server issue

I am installing on a W2k3 sp1 standard with SQL 2000 sp4 on the same machine. When I go to install to the local instance it will not connect and returns error 0x0000a410. I have verified the instance name, tried a slew of variations, ip address, with no joy. I reset the sa pw. I used a known good windows account. no joy.

Any help is appreciated.

Matt

Connection from the Enterprise Manager and/or the Query Analyser works?