Software

how it was done with W2K.

http://www.microsoft.com/technet/archive/ittasks/maintain/s2impgp.mspx?mfr=true

read through the article and follow the additional links for more detailed information

note: the .msi package is an installer and you need to create a distribution point where you can store the packages. Then advertise or assign those packages in GP. GPO rules apply.