How to Utilize Burn Policy `EngineWorkingDirectory` in Wix4

Question

I'm creating a WiXv4-Preview1 install bundle and running into a security policy issue where the installer executable can't be launched from the %TEMP% directory. I see in the release notes that I am supposed to be able to set a registry value at HKLM\Software\Policies\Wix\Burn to control this.

I have created a String Value of EngineWorkingDirectory in the above location set to C:\test and rebuilt the bundle but the Windows application log is still showing that the installer is executing out of C:\Windows\Temp\{guid}\.cr\installer.exe and is subsequently blocked. Since the documentation for v4 is still in progress I don't have anything to fall back on to understand if I'm using the capability correctly or missing something. Any help would be appreciated.

Answer 1

Got an answer to this via another communications channel. The folder specified in the registry key must already exist with the appropriate ACL permissions for the installer to extract there, otherwise is falls back to %TEMP%. Also this setting only applies to bootloaders run as an administrator. Running as local user will always extract to the user temp directory with no ability to override.

The intent is for your IT team to set the reg key via group policy to direct your extraction to a known, desired location. However, your mileage may vary getting the key and folder created in the first place depending on the level of caring of your local security team.