install apps

I have windows nt4 ws nt 2000 and win xp clients.. How do you install applcations on clients so all usrs have access to it. on their machines.. I have small network. 2 win 2k pro 3 nt 4 and 4 xp pro. When I try to install apps do not ask option to for all users. I know some new apps will ask…Thanks alex