Starting in Camtasia 8.4.0 Windows XP is no longer supported and will not be able to record system audio
Regardless of what hardware you have, you should be able to record system audio directly from the Camtasia Recorder interface. To make sure this works, be sure to verify this check box is checked in the Camtasia Recorder.
If using the PowerPoint Add-In, make sure this box is checked:
*If you are receiving some sort of error when attempting to record system audio, please submit a support ticket with us and include the error you are receiving.