cmd.exe: Determine if running in a 32 or 64 bit environment

Using %PROCESSOR_ARCHITECTURE% and %PROCESSOR_ARCHITEW6432%

Apparently, using %PROCESSOR_ARCHITECTURE% is missleading. The variable reports the bitness of the process, not the bitness of the CPU.

%PROCESSOR_ARCHITEW6432% can only be used for WOW64.

See David Wang: HOWTO: Detect Process Bitness.

However, it seems that it's possible to query the value of PROCESSOR_ARCHITECTURE directly from the registry under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment:

PowerShell:

[environment]::getEnvironmentVariable('PROCESSOR_ARCHITECTURE', 'machine')

and cmd.exe:

for /f "tokens=3 usebackq" %a in (`reg query "HKLM\System\CurrentControlSet\Control\Session Manager\Environment" /v PROCESSOR_ARCHITECTURE`) do echo %a

Using %PROGRAMFILES(x86)%

Another approach seems to be to check if the environment variable %PROGRAMFILES(x86)% (not the directory it points to) exists.

On 32-bit systems, the variable is not defined.

With wmic

With wmic.exe, the bitness (here refered to as address with) can be determined like so

C:\> wmic cpu get addressWidth

Compare that with

C:\> wmic cpu get dataWidth

In an elevated command prompt, it can alternativelly be determined as follows

c:\> wmic os get osArchitecture

Using the registry

The value of Identifier under HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0 seems to contain 64 Family if it is a 64 bit cpu, see this script.

cmd.exe: Determine if running in a 32 or 64 bit environment

Using %PROCESSOR_ARCHITECTURE% and %PROCESSOR_ARCHITEW6432%

Using %PROGRAMFILES(x86)%

With wmic

Using the registry

See also