The “reg query” technique you suggested is probably the best approach. That said--and for the benefit of some other readers--depending on the registry key you chose, you’ll have to trim off some information. For instance, if you use the configuration key (i.e. CONDOR_CONFIG under HKLM\SOFTWARE\Condor), you’ll have to trim off the configuration file name. The other option I know of offhand is the uninstall key; however, I’ll leave that one for others to explore if they are so inclined.
I am calling some condor binaries from a .BAT file I distribute to my users, but I need to find the location of the condor binaries. Of course the default is c:\condor\bin but several of my "users" have condor installed on D: or even I: etc so I cannot use a hard coded path.
I realize "reg query" can be used to search the registry, but assuming someone has done this before there is probably a best practice to use.