This seems to be something that is coming through windows messenger. You can disable the service.
Windows XP Home Click Start, then Control Panel. Double-click Performance and Maintenance. Double-click Administrative Tools. Double-click Services. Highlight/ right-click on Messenger Choose Properties and in the "Startup type" list choose Disabled. Click Stop, and then click OK.
Windows XP Professional Click Start, click Control Panel. Double-click Administrative Tools Double-click Services Highlight/ right-click on Messenger Choose Properties and in the "Startup type" list choose Disabled. Click Stop, and then click OK.
I hope this helps.
Art