When you cannot double-click on a .reg file to put something in the Windows 7 registry...

There may be a workaround. There is at my environment. At the start menu I can type regEdit at the start menu and, without pressing Enter, where regEdit appears at the start bar, I can right-click on regEdit and pick Run with Administrative Privileges (Audited) to run Registry Editor as administrator. From there I can go File > Import... to import a .reg file.