Registry editing has been disable by your administrator

Here's the command to enable registry editing using the command prompt/run dialog box:

REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableRegistryTools /t REG_DWORD /d 0 /f

Here's another way to enable it by using a vb script: http://punkisnail.blogspot.com/2009/01/enable-regedit-using-vb-script.html