I am using MEP 14 (with the latest updates) on a Windows XP Pro SP3 system.  It was working OK on an old PC.  I got a new PC and installed MEP on the new PC (as an administrator).  I registered the MPEG-2, MPEG-4, and DOLBY features and they registered OK.  I can burn a movie disc OK .

When logging in as a limited user account (LUA) and try to burn a movie disc, MEP reports that the user is a limited user and to register MPEG-2 as an administrator.

When I make the user an administrator, she can burn OK (MEP knows that MPEG-2 is registered and the Help menu to register it is dim).

I vaguely remember something similar happening when I first installed MAGIX on the original PC, but my notes don't say what I did and I don't remember what I did to work around it.  I tried the standard things to get around LUA bugs (granting permissions to the program files folder, granting permissions to the SOFTWARE key in the registry, reinstalling when the user is an administrator), but none of those work.  I saw that a few other people reported the problem on the MAGIX forum and I tried what they suggested (granting permissions to two specific keys in the registry).  I even tried granting permissions to the entire Windows folder and subfolders, but still cannot burn as a limited user.

I uninstalled MAGIX and all the other software that it installs.  I deleted the program files folders and the SOFTWARE registry keys (that is, every trace of MAGIX that I could find), but when I reinstalled (logged on as  with administrator rights), MEP already knew that the features were activated.  So MEP is storing the activation somewhere other than what I removed and that is probably that place that I need to give the limited users permission.

I tried installing MEP as both Private and Shared.  Neither seem to work any different.

The error message that comes up says that it must be activated using administrator rights or permissions must be granted to system files.  What system files?