C:\Program Files (x86)\Altiris\eXpress\Deployment Server\PCT\AClient
This is the AClient version that should be installed on all of your client machines. In order to get a list of all of the client machines that are not updated, run the following SQL query. On the line that says "SET @version = 6.x.xxx" put in the file version of the AClient.exe that is on your Deployment Server.
DECLARE @version VARCHAR(10)
SET @version = '6.x.xxx'
SELECT '-c:' + n.ip FROM computer c, nic_interface n
WHERE c.aclient_ver != @version AND n.ip != '0.0.0.0' AND c.computer_id = n.id
When this query has returned its results, right-click on those results and click Select All. Then right-click on the results again when they are all highlighted and click on Save As. Save the file somewhere that you can find it, and call the file "clients.rci". Make sure that the file is saved with an .RCI file extension.
Once that file has been created, you can close out of the SQL Query Analyzer and run the Remote Agent Installer (from the DS console under Tools > Remote Agent Installer). Go through that wizard until you reach the last step right before you click on Finish. On this step it asks for the machines that will have AClient installed. One of the buttons says Import. Click on this and then browse out to the .RCI file that you created from the query. When that file is imported, you should see in the utility a list of IP addresses of machines that it will attempt to push out the AClient. Click on Finish, and it should finish that task.
Many of the clients will likely fail to install. Often this is because those machines are either turned off or not connected to the network. If some of them do fail, you can retry the remote agent push. If certain machines are consistently failing, but you believe that they are on the network, try to first ping the machine's IP address, and, if that is successful, try to access the admin c$ share on the machine (by going to Start > Run and then typing "\\IPaddress\c$" ). Generally if the utility fails on a machine, either one or both of the above troubleshooting steps will also fail. These will show if you either cannot access that machine on the network, or if the authentication to that machine is failing.