A nice long trial and I installed SQL on Windows 7 thanks to the
following articles:

- Attempt to perform an unauthorized operation error

Giving my user the proper permissions on
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\WMI\Security

- Access denied exception

Adding the group Administrators in
secpol.msc
Local Policies
User Rights Policies
Debug Programs

http://blog.daniele.bonini.name/?p=2044