[wix-users] How to detect which version (if any) of WiX Toolset is installed on the computer?

[Tobias S]

I'd check if environment variable %wix% is present. If yes, check e.g. for
fileversion of %wix%bin\candle.exe.

Other approach is traversing the ARP information in

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall
(or without wow6432Node on x86 OS)

for the GUID {65E893AD-EDD5-4E7D-80CA-F0F50F383532}. The so found key
should be the WIX ARP Entry. If present check for BundleVersion.