network connections and start up error

whenever windows starts  ( 5150 with XP home) i am confronted with an error message that says 'windows cannot find 'dust.exe'' and this occasionally pops up while im working, any ideas on a fix ? also i have got problems in my network connection properties menu, i am having broken up sound while doing netmeeting audio conversations, i have been told to disable the QoS packet scheduler in network connection properties however it simply wont let me uncheck the box. to explain where im talking about go to control panel, network connections ( then right click my active connection) click properties then the tab 'networking'. any ideas on how to uncheck it ? any help is greatly appreciated.