Can't install SCCM client on some computers

[chicagotech]

We are running SCCM 2007 on Windows 2008 R2. We have about 600 computers in windows 2008 domain, 80% are XP and 20% are Windows 7. We can push SCCM client installation on 90% workstations without any problems. We can’t push the installation to other 10%. We find the problem may be the firewall. Or if we disable the firewall on the client, the SCCM client will be installed automatically. We setup Domain Group Policy to enable firewall on all computers. The question is why we can install sccm client on most computers but others. We don't want to disable the firewall and go to each workstation to install the SCCM client. What's the solution for this case?

[chicagotech]

Case 1: The we create OU called workstation with Remote Management Policy that enables ICMP, Define Inbound port exception, Allow inbound remote administration exception, and Allow inbound remote Desktop exception. If we forget to move the new setup computers to the group, the policy doesn't apply to the computer and the computer firewall will block SCCM client installation.

Case 2: If the computer has name resolution issue, you may not be able to install the SCCM client.