Determining 64-bit OS

Determining 64-bit OS

• Deb Magsam

  You can do an IsWow64Process api call to see.

  typedef BOOL (WINAPI *LPFN_ISWOW64PROCESS) (HANDLE, PBOOL);
  

  BOOL IsWow64()
  {

  BOOL bIsWow64 = FALSE; // assume 32 bit
  
  // can't call IsWow64Process on x32, so first look up the entry point in kernel32
  LPFN_ISWOW64PROCESS fnIsWow64Process = (LPFN_ISWOW64PROCESS)GetProcAddress(GetModuleHandle ("kernel32"),"IsWow64Process");
  // if we have an entry point for IsWow64Process, we can call it
  if (NULL != fnIsWow64Process)
  {
  if (!fnIsWow64Process(GetCurrentProcess(),&bIsWow64))
  {
  // handle error
  }
  }
  return bIsWow64;
  }

  
  

• globemast

  Check the "PROCESSOR_ARCHITECTURE" environment variable. If it's not "x86" it's 64 bit.
  
  I think the valid values are "AMD64", "x64" and "IA64" (obviously not relevant to Vista)
  
  

• Jonas Beckeman

  If you install a 32bit OS on a 64bit processor, the value will be "x86"
  
  

• CorneVR

  Though couldn't you install the 32-bit OS on any of those

  Dan

  
  

• raj.ramesh

  I'm not really sure, but I guess you could check to see if the 32-bit Program Files folder exists (c:\Program Files (x86)).

  Probably not the simplest way, but the only way I can think of without messing around on 64bit Vista for a while :)

  Andy

  
  
  
• Determining 64-bit OS