Hi andre_bergh and
Why havent you upgraded the other machines to XP. Thats where I would start. You'd be a lot safer with XP.
Disabling the XP fire wall and running a third party one would give you a greater amount of protection too.
Try running the Ad-aware and spy-ware programs found in Here
then post back .
If you know which is the offending machine try downloading HiJackthis to a folder in your "C" directory. Run it from there and then post the log in the HJT forum . Someone there will be more than pleased to help you in reading your log and advising you of any problem found and how to remove it.
Let us know how you go.
Edited by JackTheHaack, 31 January 2005 - 04:18 PM.