Running as admin makes no difference, tried that so even if you put it in a batch file wouldn't work.
Go to regedit in Windows 7
Go to key
HKEY_CLASSES_ROOT\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}
This is just where you can change the Computer Name on the Computer Name icon to be the, erm, Computer Name

it will change automatically.
Anyway. Right click the key and look at the permissions. You'll notice TrustedInstaller is the only one that has Full Control. Administrators don't and that's the problem with merging the reg key. To get the reg key to merge, you have to go to the key first and set the permissions on Administrators to Full Control.
So that's the problem.