Symptom: in Visual Studio 2008, you attempt to add a new WebContentForm and associate it with a MasterPage. You receive an error dialog "Requested Reqistry Access is not allowed".
Don't ask me what caused this; I'm guessing that the registry keys involved had their access denied due to removal of a previous version of Visual Studio, leaving the new guy (Visual Studio 2008) in the lurch.
Here's the fix:
Download "subinacl" here. This is a command-line tool that enables administrators to obtain security information about files, registry keys, and services, and transfer this information from user to user, from local or global group to group, and from domain to domain.
After installing subinacl.exe (it will be in the C:\Program Files\Windows Resource Kits\Tools folder.), drop to a command prompt and run the following batch file, which you have saved in the same folder with the filename "FIX.bat":
subinacl /subkeyreg HKEY_CLASSES_ROOT\VisualStudio.vbproj.9.0 /grant=administrators=f
subinacl /subkeyreg HKEY_CLASSES_ROOT\VisualStudio.vbproj.9.0 /grant=users=f
subinacl /subkeyreg HKEY_CLASSES_ROOT\VisualStudio.vbproj.9.0 /grant=system=f
subinacl /subkeyreg HKEY_CLASSES_ROOT\VisualStudio.csproj.9.0 /grant=administrators=f
subinacl /subkeyreg HKEY_CLASSES_ROOT\VisualStudio.csproj.9.0 /grant=users=f
subinacl /subkeyreg HKEY_CLASSES_ROOT\VisualStudio.csproj.9.0 /grant=system=f
BAM! All fixed! Have fun.