If you want to do agentless monitoring of a Windows 2003 host, you need to configure WMI to allow remote querying.

1. Open Computer Management (Administrative Tools). Expand Services and Applications. Right-click WMI Control, then click Properties.
2. Select the Security tab, click the Root namespace, then click the Security button at the bottom.
3. Add the user that will need access to WMI. This is usually the service account running the System Center agent on the host that will monitor this host.
   When adding the account, be sure to allow for Remote Enable.

If Windows Firewall is in use, you also have to allow for remote management:

1. Open a command prompt.
2. Type the following to allow remote management through the firewall:

   netsh firewall set service RemoteAdmin enable

If the service account is not a local admin on the host, you will also have to configure (remote) access to DCOM:

1. Open Component Services (Start → Run → dcomcnfg).
2. Expand Component Services, then expand Computers. Right-click My Computer, click Properties.
3. Click the COM Security tab. In the section Launch and Activation Permissions, click Edit Limits to bring up the security dialog.
4. Add the System Center agent's service account, and set to allow Remote Launch and Remote Activation.
   Finally, click OK to confirm changes and return to the previous dialog.
5. In the section Access Permissions, click Edit Limits to bring up another security dialog.
6. Click the ANONYMOUS LOGON user, and check to allow Remote Access. Click OK.