I have a 32-bit application that I've been maintaining for about 12 years and it runs on every Windows platform up to Windows 7. In all that time I've been using CWinApp::GetProfileXxxx() and CWinApp::WriteProfileXxxx() calls to read and write my program settings (about 70 settings) in the Registry. The settings are read from the Registry at start-up and written to the Registry when the program closes. There is also a method for the user to read and write the program settings to an INI file using the same code as the Registry access.
On my Windows 7 system the Registry read/write works just like it always has on all previous Windows versions. However, on some customer's Windows 7 machines there appears to be a problem with the Registry access. The program settings are either not being read from the Registry or are not being written to the Registry. I think the settings are not being written – but I don't know that. When the user uses the INI file the settings appear to be read and written.
The customer has complained a bit (I'd complain too) but doesn't have the time or doesn't want to take the time to run some simple tests for me to find out what's going on with his Windows 7 system.
So here is my question: Are there any user account settings or permissions that can block the program's access to the Registry? He claims he is an Administrator but I can't even get him to verify that.