Not able execute CreateProcess with PhotoViewer.dll

Question

In my application there is an interface where user can select any file and open in its default application depending on the file association.

I am using FindExecutable and CreateProcessAsUser with Explorer token.

Now the problem is in the case of picture files say .jpg, FindExecutable returns "C:\Program Files\Windows Photo Gallery\PhotoViewer.dll", then CreateProcessAsUser returns "ERROR_BAD_EXE_FORMAT(193) %1 is not a valid Win32 application.". I was passing NULL as the second parameter for CreateProcessAsUser, sending executable path in lpCommandLine(eg: CreateProcessAsUser(hToken, NULL, szCmdline, ...)).

Can anyone help me in solving this?

Regards, Manoj

Answer 1

Hi, how about using ShellExecuteEx with a properly initialized structure? This should invoke the default action on a given file.

Answer 2

A Win32 executable has extension .EXE; a DLL is not an executable. CreateProcess cannot create a process with just a .DLL. The missing .EXE is "rundll32.exe".

However, that's not what you are after: you want the Shell behavior. ShellExecuteEx() is usually the most convenient function. AssocQueryString() may be appropriate in this case, with the right flags: ASSOCSTR_EXECUTABLE to get the executable in case it's not yet running, and ASSOCSTR_DDEAPPLICATION etc. in case the application already runs.