Find Window's Owning App -- Win32 API

GetWindowThreadProcessId()

If that doesn't help, have you tried passing GetWindowLong(GWL_HINSTANCE) to GetModuleFileName()?

Also see KB article Q119163

Yes, I have tried the proper combination of GetWindowLong() and GetModuleFileName(), but as I mentioned, under Win 95 it only works for the current app, not other apps. (Win NT has the same limitation because both are Win32.) Apparently this is because other apps (i.e. other processes) run in a different address space under Win32.

Per Alexo's note, I checked knowledge base article Q119163, but it appears this approach only works for Windows NT, because it looks through the registry for what appears to be an NT specific key, "HKEY_PERFORMANCE_DATA", if I am reading it properly. The article says it applies to NT 3.1 & 3.5; it does not mention Win 95. I need a solution for any Win32 environment.

Thanks, that should do it, but I do still have a problem: where the heck do I get ToolHelp32.dll? My Win 95 PC has the 16 bit version, ToolHelp.dll, but that is it. According to the documentation I have, the ToolHelp32 functions are actually in Kernel32.dll, but they are not exported. Do I need to get the Win 95 SDK or something?

The tool help functions reside in the operating system kernel. The following example provides a platform-independent approach to accessing the tool help functions.

#include <tlhelp32.h> // needed for tool help declarations  
 
// Type definitions for pointers to call tool help functions.
typedef BOOL (WINAPI *MODULEWALK)(HANDLE hSnapshot,
    LPMODULEENTRY32 lpme);
typedef BOOL (WINAPI *THREADWALK)(HANDLE hSnapshot,
    LPTHREADENTRY32 lpte);
typedef BOOL (WINAPI *PROCESSWALK)(HANDLE hSnapshot,
    LPPROCESSENTRY32 lppe);
typedef HANDLE (WINAPI *CREATESNAPSHOT)(DWORD dwFlags,
    DWORD th32ProcessID);
 
// File scope globals. These pointers are declared because of the need
// to dynamically link to the functions.  They are exported only by
// the Windows 95 kernel. Explicitly linking to them will make this
// application unloadable in Microsoft(R) Windows NT(TM) and will
// produce an ugly system dialog box.
static CREATESNAPSHOT pCreateToolhelp32Snapshot = NULL;
static MODULEWALK  pModule32First  = NULL;
static MODULEWALK  pModule32Next   = NULL;
static PROCESSWALK pProcess32First = NULL;
static PROCESSWALK pProcess32Next  = NULL;
static THREADWALK  pThread32First  = NULL;
static THREADWALK  pThread32Next   = NULL;
 
// Function that initializes tool help functions.
BOOL InitToolhelp32 (void)
{
    BOOL   bRet  = FALSE;
    HANDLE hKernel = NULL;
 
    // Obtain the module handle of the kernel to retrieve addresses of
    // the tool helper functions.
    hKernel = GetModuleHandle("KERNEL32.DLL");
 
    if (hKernel){
        pCreateToolhelp32Snapshot =
            (CREATESNAPSHOT)GetProcAddress(hKernel,
            "CreateToolhelp32Snapshot");
 
        pModule32First  = (MODULEWALK)GetProcAddress(hKernel,
            "Module32First");
        pModule32Next   = (MODULEWALK)GetProcAddress(hKernel,
            "Module32Next");
 
        pProcess32First = (PROCESSWALK)GetProcAddress(hKernel,
            "Process32First");
        pProcess32Next  = (PROCESSWALK)GetProcAddress(hKernel,
            "Process32Next");
 
        pThread32First  = (THREADWALK)GetProcAddress(hKernel,
            "Thread32First");
        pThread32Next   = (THREADWALK)GetProcAddress(hKernel,
            "Thread32Next");
 
        // All addresses must be non-NULL to be successful.
        // If one of these addresses is NULL, one of
        // the needed lists cannot be walked.
        bRet =  pModule32First && pModule32Next  && pProcess32First && 
                pProcess32Next && pThread32First && pThread32Next && 
                pCreateToolhelp32Snapshot;
    }
    else
        bRet = FALSE; // could not even get the module handle of kernel
 
    return bRet;
}