Windows – Correct technique to find application in 32 and 64 bit versions of Vista/Windows 7 from CMD.EXE

64-bitbatch-filewindowswindows-command-prompt

BACKGROUND

I have an existing CMD script that works fine. It launches an app from PROGRAM FILES like so

"%PROGRAMFILES%\MyApp\app.exe"

PROBLEM

it works fine on 32-bit versions of Windows (Vista, Windows 7)
but on 64-bit versions of Windows the app will be installed into "Program Files (x86)" and not "Program Files" (which is what happens on the 32bit OS)

WHAT I AM LOOKING FOR

A script that robustly handles both cases (i.e. it "does the right thing" depending on the OS it is on)
a method that uses only those features found in CMD.EXE. I Am curious about solutions that use Powershell, etc, but those don't help me – Powershell will not be on the machines this script will run.

Best Answer

Similar to Matt's correct answer. Basically in this version the complete path is verified.

SET AppExePath="%ProgramFiles(x86)%\MyApp\app.exe"
IF NOT EXIST %AppExePath% SET AppExePath="%ProgramFiles%\MyApp\app.exe"
%AppExePath%

Related Solutions

How to add assemblies in a 64-bit machine

You need to quote around the path to gacutil because it has spaces in it. Try:

C:\Windows\Microsoft.NET\Framework64\v2.0.50727\RegAsm blabla.dll "C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin\NETFX 4.0 Tools\GacUtil" -i blabla.dll

Windows – %ProgramFiles% differences on 64bit Windows

When a 32-bit application launched in a 64-bit Windows addresses the system environment variables %ProgramFiles% or %commonprogramfiles%, the WoW64 subsystem replaces the values of these variables with the values of the variables %ProgramFiles(x86)% and "%commonprogramfiles(x86)%. Thus, for instance, %ProgramFiles% will be opened as "C:\Program Files (x86)" when addressing from a 32-bit program.

This behavior is determined by the register redirection system that provides backward compatibility of 32-bit software with 64-bit operating systems. The 32-bit environment is emulated for 32-bit programs even despite the fact that the data they are addressing is located in a different place.

To avoid such a redirection in a 32-bit program, you should use the %programfiles% or %COMMONPROGRAMFILES% (i.e. with reverse case) environment variables or the KEY_WOW64_64KEY flag when accessing the corresponding register nodes.