Posted 03 January 2011 - 01:23 AM
As with any strange behaviour, you should ensure the PC is free of malware. If the one-hour problem is predictable, you should keep an eye on your PC at that time (and information such as Task Manager) to see if anything is happening, whether it's you or the PC doing it.
I would check for any issues in the sound section of Device Manager and in Control Panel/Sounds to see if there is anything amiss (before and after the problem). In the Audio tab, the default devices should be what you expect and that mixers are present when you select the Volume button for the play and record sections.
Obviously the printers have nothing to do with the audio. It appears the reboot is reinstalling whatever was apparently going missing. You need to do a bit more checking yourself and post back with more details of your PC setup. Also if this started out of the blue or coincident with any events (such as installing a new printer!).