Unable to restore some default file associations. Note: you must be an administrator or a power user on this machine in order to change file associations.

This error occurs when the devenv command-line switch /AssociateFiles is used, but the current user rights do not allow access to the HKEY_CLASSES_ROOT section of the registry. When you run Visual Studio on Windows Vista, you must run devenv as an administrator to use the /AssociateFiles (devenv.exe) switch.