Altiris 7.1 Adding Drivers for New Systems to Boot into PXE

Hello All,

      We have 3 new systems that I’d like to get their drivers added to our Altiris 7.1 environment for PXE boot up.  When I boot them currently I'm getting the retry error.  If somebody has had any luck adding any of the drivers below I'd truly appreciate it if you could give me a step by step guide to get this done.  I'm not an Altiris expert so any help you guys can provide is truly appreciated.

Lenovo T440P    20AN-0069US
Lenovo T440S     20AN-005QUS
Lenovo Edge73  10AU-002PUS