The infrastructure of sound, video, modems, wifi etc are indeed missing from windows PE. Devcon.exe from Microsoft is a command line tool that takes the place of Device Manager and works well within Windows PE. I have used it many times. Using the switch 'driverfiles' should help identify the drivers loaded per device. Eurosoft do have the ability to diagnose sound for WinPE 1.5 and 2.x but it is bundled up in their software package. Since I left the company I do not think they had anyone to continue this development and doubt they would be able to help if you were thinking of asking them.