To those of us who have horrible audio problems under 2008 Server by default (crackling, skipping, hissing, etc) and it worked fine in Vista, consider making the following registry change:

Key: HKLM\Software\Microsoft\Windows NT\CurrentVersion\multimedia\SystemProfile
Value: SystemResponsiveness
Type: REG_DWORD
Radix: Decimal
Data: 20


This makes Server 2008 behave more like Vista SP1 when scheduling CPU for audio/multimedia threads.

do I need to use a qword if I'm running 64 bit? (dword is 32, qword is 64)

Nope, it is a REG_DWORD value.
It's already present, so this is an edit, not a creation.