To ensure that all systems that are intended and targeted for the ConfigMgr client installation. The best client deployment method is using AD GPO that will apply 3 settings.
1. the ccmsetup parameters are place in the registry
2. the WSUS URL is place in the registry.
3. applies the ADM Client Assignment template.
Enable WSUS/SUP Client Installation. In the GPO add the WSUS URL for your SUP Site Role. As clients join the domain or connects to the network, the Windows Update Agent will scan against your WSUS server and the ConfigMgr client will be detected as not installed and WSUS will install the client treating the client as if it was a critical update.
The installation will start about 2 to 3 minutes after the client is detected as not installed. This method will also upgrade a client that is lower than the published version in WSUS. If a client is already installed with the right version, the client will be re-assigned to your site if not already assigned. Also as part of this GPO you will want to add the ADM Client Assignment template. This is comes with ConfigMgr 2007. This template will keep clients assigned to the site of choice.
Two things will happen automatically for you. If the client is un-installed for any reason, WSUS will re install the client on the next WSUS scan. If the client is re assigned to another site, the ADM template with automatically reassign the client back to the originating site code immediately.