"Requested registry access is not allowed" error with Forms Server and/or MOSS
I bumped into this error message with a customer MOSS + Forms Server installation, that had it's key recently upgraded to an enterprise RTM version from a Beta 2 Technical Refresh (B2TR) key. Upon opening InfoPath-forms via Forms Server users would get a "Requested registry access is not allowed" -error.
After playing around a bit with the problem, and using regmon (https://www.microsoft.com/technet/sysinternals/utilities/regmon.mspx), I found out it was a security-related problem with this registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office Server\12.0\OfficeServerPremium
To fix this, I added WSS_WPG and WSS_ADMIN_WPG with the following permissions for those keys:
WSS_WPG (read), WSS_ADMIN_WPG (Full Control)