I want to do a new clean install of FSX including the numerous ATC voice mods I've added. Where are these files located, so that I can back them up to add to my new FSX.

Assuming you're talking about EVP mods, the two files it modifies are:

 

usenglishbig.gvp - this is modified directly unless you use the accelerated voicepack, in which case it is renamed to USEnglisgBig.gvp.evpOrg and a new file called Evp.Accelerated.gvp is created. I believe these files are in the FSX Sound folder.

 

The other file which is modified if you add new airlines, is airlines.cfg. Not sure where that is, but you should be able to find it quite easily.

 

Personally I would also Export my own EVP mods to an external backup so if all else fails I can re-apply them.

DickB,

 

Thanks for the info  I was aware of the airlines.cfg but not the .gvp files. Good idea about the external backup.