CreateProcess not retrieving correct PID for OSK - excel

Question

In Windows 7, the following Excel VBA 7.1 snippet successfully launches the On-Screen Keyboard (OSK.EXE) but the value of the dwProcessID member retrieved from the 'proc' (process information) parameter (passed ByRef) does not match that, or any other PID, displayed by task manager.
Type PROCESS_INFORMATION
hProcess As Long
hThread As Long
dwProcessID As Long ' Integer doesn't work either
dwThreadID As Long
End Type
Declare Function CreateProcessA Lib "kernel32" (ByVal _
lpApplicationName As Long, ByVal lpCommandLine As String, ByVal _
lpProcessAttributes As Long, ByVal lpThreadAttributes As Long, _
ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, _
ByVal lpEnvironment As Long, ByVal lpCurrentDirectory As Long, _
ByRef lpStartupInfo As STARTUPINFO, ByRef lpProcessInformation As _
PROCESS_INFORMATION) As Long
Dim proc As PROCESS_INFORMATION
Dim start As STARTUPINFO
start.cb = Len(start)
If CreateProcessA(0, "OSK.EXE", 0, 0, 1, NORMAL_PRIORITY_CLASS, 0, 0, start,
proc) <> 0 Then
WaitForInputIdle proc.hProcess, INFINITE
MsgBox CStr(proc.dwProcessID), vbInformation, "Process ID" ' Wrong for
OSK, but correct for Notepad and Calc
CloseHandle (proc.hProcess)
CloseHandle (proc.hThread)
End If
For OSK, it seems that the proc.hProcess value is incorrect. I checked the process ID value of proc.dwProcessID against the PID listed for OSK in Task Manager, and they don't match. Indeed, proc.dwProcessID isn't listed for any process (even in Process Explorer), so it seems that the PROCESS_INFORMATION Type is not receiving correct outputs.
Everything works fine for NOTEPAD and CALC though. Equivilent code compiled in VB.NET behaves properly with OSK, so what's different about VBA that causes CreateProcessA to work incorrectly with OSK?
Thanks in advance,
John.

Answer 1

It could be that the executable you are launching (OSK.EXE) execute another process or does some job and exit very quickly so when you look in process explorer you cannot find anything.
If the code inside the "if" is not executed I would try to get the error with GetLastError call.

Answer 2

I think you are encountering issues like https://learn.microsoft.com/en-us/office/vba/language/concepts/getting-started/64-bit-visual-basic-for-applications-overview.
Long is not a good replacement for pointers, in this case should be
Type PROCESS_INFORMATION
hProcess As LongPtr
hThread As LongPtr
dwProcessID As Long
dwThreadID As Long
End Type
Declare Function CreateProcessA Lib "kernel32" (ByVal _
lpApplicationName As LongPtr, ByVal lpCommandLine As String, ByVal _
lpProcessAttributes As LongPtr, ByVal lpThreadAttributes As LongPtr, _
ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, _
ByVal lpEnvironment As LongPtr, ByVal lpCurrentDirectory As LongPtr, _
ByRef lpStartupInfo As STARTUPINFO, ByRef lpProcessInformation As _
PROCESS_INFORMATION) As Long
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