I realize this is a late response, but just in case someone else is wondering:

The Registry fix tricks the BF2editor  installer into thinking that you have BF2 installed.   The BF2editor does not need BF2 to run.   BF2editor default is installed into the BF2 folder, which it will create if it's not there.

There is a tutorial on the BF2 editor site on how to set up BF2editor for use with BF2142.