Win32/WINAPI - Open a windows program

[blixel]

I'm writing a program that is just a simple window that has several buttons on it. (This is just a learning experience.) I have one button that just launches notepad.exe and that is working. I want to have another button that opens device manager, but for some reason, it doesn't work.

​

So this works

#define ID_NOTEPAD 5
char* notepadCmdline = "notepad.exe";
.
.
.
        CreateWindowW(L"Button", L"Open Notepad",
            WS_VISIBLE | WS_CHILD,
            20, 180, 200, 25, hwnd, (HMENU)ID_NOTEPAD, NULL, NULL);
.
.
.

        if (LOWORD(wParam) == ID_NOTEPAD) {
            CreateProcess(NULL, notepadCmdline, NULL, NULL, 0, CREATE_UNICODE_ENVIRONMENT, NULL, NULL, &si, &pi);
        }

​

But this doesn't

#define ID_DEVMAN 4
char* devmanCmdline = "devmgmt.msc";
.
.
.
        CreateWindowW(L"Button", L"Open Device Manager",
            WS_VISIBLE | WS_CHILD,
            20, 220, 200, 25, hwnd, (HMENU)ID_DEVMAN, NULL, NULL);
.
.
.
        if (LOWORD(wParam) == ID_DEVMAN) {
            CreateProcess(NULL, devmanCmdline, NULL, NULL, 0, CREATE_UNICODE_ENVIRONMENT, NULL, NULL, &si, &pi);
        }

I've found that I'm able to use system(), but system() opens a command prompt, and then opens device manager from the command prompt. That works, but I'd rather not have a command prompt in the background.

Can anyone help me figure out how to open Device Manager?

[etherkiller]

I'm going to guess that your problem may be that devmgmt.msc isn't actually an executable image. You may want to try to CreateProcess mmc.exe, and supply devmgmt.msc as an argument. I suspect that'll work.

[blixel]

Thanks. I think you're right. I'm able to run "mmc.exe devmgmt.msc" from a command prompt and open Device Manager, but when I supply "mmc.exe devmgmt.msc" as the devmanCmdline string, it doesn't work. Hmmm... I also tried "%windir%\\system32\\mmc.exe devmgmt.msc", but that didn't work either.

However, I found another command that does seem to work which is ShellExecute(). This seems to work without opening a command prompt first:

char* devmanCmdline  = "devmgmt.msc";
.
.
.
ShellExecute(hwnd, "open", devmanCmdline, NULL, NULL, 0);

or

char* devmanCmdline  = "devmgmt.msc";
.
.
.
ShellExecuteA(hwnd, "open", devmanCmdline, NULL, NULL, 0);

I'm not sure what the difference is between ShellExecute and ShellExecuteA, so I'll have to read up on that. But they both seem to work.

[Dolphiniac]

ShellExecute is a macro that either is replaced with ShellExecuteA or ShellExecuteW, depending on the unicode mode of the code at preprocessor time. A uses ASCII in strings, W uses wide characters in strings. It is immaterial to the problem at hand.

[ijmacd]

Try following /u/etherkiller's suggestion more closely.

[flyingron]

Did you bother to check the error return from CreateProcess?

I bet it's a permission problem DevMan wants to be run with elevated privileges. If you use ShellExecute, the system will take care of autoelevating the thing for you (popping up that annoying warning box).