I have a batch file that is a wrapper around an installer. This batch file checks the error level returned by the installer and prints accordingly.
I noticed that if I execute set ERRORLEVEL=0 in a command prompt right before kicking off the batch file (in the same command window/environment), the installer never messes with the errorlevel and my batch script always returns passed. I would assume %ERRORLEVEL% is a variable defined by Windows and is used specifically to print out errors from programs and scripts and that using the variable in a batch file or something else would be 'at your own risk' because it could be changed at any moment by another process.
From what it seems like, when I set errorlevel in the given environment, it then somehow terminates the use of errorlevel as a holder of the exit code. Does anyone know why this is? To me its just weird unexpected behavior. Any information on the subject would be greatly appreciated!