Updating Anti Virus Software on Client P

We run McAfee antivirus but we seem to have a problem updating the virus patterns as the user doesnt have the rights to run the update. Instead of configuring all the client pcs is there a way i can run an activate to update all the virus patterns on the users pcs from the server etc. i know this is probably an easy one but there really is only me here as an admin and i have much more pressing issues to deal with so any help would me most appreciated. Thanks again!