This only works in Windows XP, and it disables Windows
messenger which is how they get in. You cannot disable
windows Messenger in 98 nor ME

Click Start - Control Panel
Click Admin Tools
Click Component Services
Double click services local
Double click Messenger to bring up the options psnel
Right click the highlighted line and choose properties
click thye stop button
select disabled or manual on the start up style drop down
menu
click ok

No more popups

Ian