Automatically install programs

Hi all, running SBS2003 and XP Pro SP2 workstations.

I would like to know how I can assign and automatically install programs for
client stations.
I can assign an application through the Server Administrator, but all that
does is place an icon in the user's desktop. Some users may not end up
seeing these files if their desktops are cluttered.
So how would I be able to assign an application, and when the user logs on,
have it automatically install.

Thanks.
Jason



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