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 may need to account for:
|CPU Hardware||Operating System||Process|
|Windows XP (16 bit compatibility)||32||32||16|
|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)|
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.
:: Installed OS
IF %PROCESSOR_ARCHITECTURE% == x86 (
IF NOT DEFINED PROCESSOR_ARCHITEW6432 Set _Bitness=32
Echo Operating System is %_Bitness% bit
Via David Wang’s blog post: Detect OS Bitness
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 If %PROCESSOR_ARCHITECTURE% == x86 ( Set _ps_bitness=32 ) ELSE ( Set _ps_bitness=64) Echo Process is %_ps_bitness% Bit
:: 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 apps
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.