These popups can be quite annoying.
To get rid of them (in XP), go to
-->
Administrative tools (should be somewhere in your startmenu/programs)
then select
-->
services
Then you'll get a list with all the local services that may be running. In this list you will find
-->
Messenger
highlight this service, on the left you'll see an option to
-->
stop
This will only stop this service untill you reboot. To stop it completely, rightclick on
Messenger will give you more options and control over this. eg, you can opt for a manual start or automatic.