Norton error 1406 - editing windows registry

I am trying to install Norton Internet Security 2005 on my computer and get error message 1406. Norton's site advises modifying registry keys and gives instructions, but I cannot follow them at a critical point. They advise (1) click start - run "regedt32", (2) right click HKEY_LOCAL_MACHINE, click permissions, click system and check ALLOW for the read and full control entries then click OK, (3) double click HKEY-LOCAL-MACHINE, click software and do the same for it. Fine up to there, but then they say double-click software to expand it (okay), click the next registry key listed in the error (WHAT IS A REGISTRY KEY AND WHERE WOULD THE ERRORS BE LISTED?) stating for example that if the registry key that you see in the error message referenced symantec then I should change the permissions for that. I am supposed to do that for every registry key listed in the error message. My error message when trying to install Norton did not list any registry keys. Does anyone know where to find these "errors?" Thank you in advance for any help.