avast4 - winXP for all users?

hi together,

yesterday i installed avast4 with my user account under windows xp.
i would like avast4 to start for all users on my pc. other users do have only limited rights. when someone else starts xp a message comes up that the licence key can only be typed in from someone with admin rights. (avast does not start automaticly for other users)

what do i have to do that avast starts for all users when starting winxp?

in advance many thanks for your help.

kind regards

MIMAMO