Detecting 64 bit vs 32 bit Windows

Before starting to look at this, its important to be clear about what you mean by "64 bit". You can have a 64 bit CPU, a 64 bit operating system and a 64 bit process running. It is equally possible to have 64 bit CPU, a 32 bit operating system installed and a 16 bit process running.

The table below shows a few of the combinations you need to account for:

  CPU Hardware Operating System Process
Windows 3.1 16 16 16
Windows 95/NT 32 32 32
Windows XP (16 bit compatibility) 32 32 16
Windows XP 32 32 32
Windows XP on new hardware 64 32 32
Windows 7/2008 on old hardware 32 32 32
Windows 7/2008 (32 bit compatibility) 64 64 32 (WOW)
Windows 7/2008 64 64 64

Detect 64 bit processor hardware

In Vista and greater, you can use wmic os get osarchitecture, or in WMI Win32_ComputerSystem/OSArchitecture sadly this is not supported in XP or 2003
There are a number of promising looking options in WMI and Systeminfo, but they all pertain to the OS not the CPU.

Detect a 64 bit Operating System

:: Installed OS
Set _Bitness=64
Echo Operating System is %_Bitness% bit

Via David Wang’s blog post: Detect OS Bitness

Detect a 64 bit Process

On Windows 7, running C:\windows\SysWOW64\cmd.exe will launch a 32 bit instance of CMD.exe even if the OS is 64 bit. Applications that are compiled for a 32 bit processor will run in a similar way. We can detect this with the %PROCESSOR_ARCHITECTURE% environment variable.

:: Process
   Set _ps_bitness=32
   ) ELSE ( Set _ps_bitness=64)
Echo Process is %_ps_bitness% Bit

Program Files location for 32 bit applications

:: Program Files location for 32 bit apps
If DEFINED ProgramFiles(x86) Set _programs=%ProgramFiles(x86)%
If Not DEFINED ProgramFiles(x86) Set _programs=%ProgramFiles%
Echo Program Files location for 32 bit apps:
Echo %_programs%

Program Files location for 64 bit applications

:: Program Files location for 64 bit apps
Echo %ProgramFiles%

C:\Windows\System32\ will contain either 32 bit or 64 bit programs, the path has been kept as 'system32' for backwards compatibility. When running 32 bit WOW, the 32 bit versions are called from C:\Windows\SysWOW64\

“It's not so much that we're afraid of change or so in love with the old ways, but it's that place in between that we fear... it's like being between trapezes” ~ Marilyn Ferguson


Q556009 - How to check if a computer is running a 32 bit or 64 bit Operating System.

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