How to make a batch file that changes the wallpaper of a computer

Question

I want to create a batch file that is later going to be converted to an exe that changes the wallpaper of my computer as soon as I open it. Sorry I have no idea how to do this D:

Answer 1

The usual answer to this question is

reg add "HKCU\Control Panel\Desktop" /v Wallpaper /t REG_SZ /d  "c:\somewhere\something.bmp" /f

to set the adecuated entry in the registry, followed by

RUNDLL32.EXE user32.dll,UpdatePerUserSystemParameters

to inform the system of the changes.

BUT, from windows Vista this approach does not work. Or at least not as intended. The changes to the registry will apply on new logon. The only robust way to get the wallpaper changed instantly is to use the windows api.

For a powershell solution, you can find a solution here

If you have access to a C compiler, this code should do the same (tested with mingw-gcc)

#include <windows.h>
int main(int argc, char **argv)
{
    if (argc < 2) return 1;
    if (! SystemParametersInfo(
            SPI_SETDESKWALLPAPER, 
            0, 
            argv[1],  
            SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE 
        )) return 2;
    return 0;
}