Binaryworld - Determine whether a program is 16- or 32-bit ... [ VB -> Windows ]

Even if we're living in a 32-bit world, and closer and closer to the 64-bit day, 16-bit programs are still running out there. Knowing whether a given EXE is 32-bit or not can be useful when you have to arrange version checking routine, for example to detect which version of a product is installed.

The Win32 SDK makes available a multi-use function called SHGetFileInfo() that serves the purpose. It is declared like this:

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Type SHFILEINFO
hIcon As Long
iIcon As Long
dwAttributes As Long
szDisplayName As String * MAX_PATH
szTypeName As String * 80
End Type

Public Const SHGFI_EXETYPE = &H2000

Public Declare Function SHGetFileInfo Lib "shell32.dll" Alias "SHGetFileInfoA" _
  ( ByVal pszPath As String, ByVal dwFileAttributes As Long, _
  psfi As SHFILEINFO, ByVal cbFileInfo As Long, ByVal uFlags As Long ) As _
  Long

Its usage is:
dw = SHGetFileInfo(exename, 0, sfi, Len(sfi), SHGFI_EXETYPE)

The returned low word contains the signature of the executable. You must compare it against the following values:

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Const WIN32_GUI = &H4550 ' PE, Win32
Const WIN16_GUI = &H454E ' NE, Win16
Const WIN16_DOS = &H5A4D ' MZ, MS-DOS

You can obtain the low word in this way:

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dw = SHGetFileInfo(exename, 0, sfi, Len(sfi), SHGFI_EXETYPE)
lowWord = dw And &H7FFF