connection refused 274D/10061

Help me ,please.

What difference between installation PGSQL on win-2000 and
win-2000-server or on WIN-XP ?

When i try to connect to installed PGSQL on win-xp or win-200-server
from other host of local net, i get the message :

Connection refused (0x0000274D/10061)
       Is the server running on host "192.168.1.21" and accepting
       TCP/IP connections on port 5432?

When i installing PGSQL on Win-2000 (not server) i have no this
problem.

All changes in  pg_hba.conf and in postgresql.conf have done.Maybe i must to  open
some extra parameters in postgresql.conf file or do something else ?

Os name : Microsoft Windows 2000 Server
Version : 5.0.2195 Service Pack4 Build 2195.

Version of PGSQL : 8.0
Excuse me for my poor English,please.
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Best regards Платонов Владимир (Platonov Vladimir from Russia).  mailto:platonovvp@agrisovgaz.ru