How to auto-hide the taskbar from the command line

To autohide the taskbar from a cmd prompt or in a .cmd or. bat file:

Windows 7 (StuckRects2)

powershell -command "&{$p='HKCU:SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\StuckRects2';$v=(Get-ItemProperty -Path $p).Settings;$v[8]=3;&Set-ItemProperty -Path $p -Name Settings -Value $v;&Stop-Process -f -ProcessName explorer}"

Windows 10 (StuckRects3)

powershell -command "&{$p='HKCU:SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\StuckRects3';$v=(Get-ItemProperty -Path $p).Settings;$v[8]=3;&Set-ItemProperty -Path $p -Name Settings -Value $v;&Stop-Process -f -ProcessName explorer}"

Explanation

The registry key which stores this value also stores a number of other settings. Since we only want to change position 9 ($v[8] in the cmd) of that registry setting, we need to preserve the other settings.

Normally from cmd, it's enough to use a reg add command to modify the registry, but we use powershell because it makes it easy to preserve the other settings stored under the same registry key.

Explorer also needs to be restarted to pick up the change. We use Stop-Process because Windows automatically restarts Explorer when it is stopped.

Note: change $v[8]=3 to $v[8]=2 in the commands above to undo this change (if you want the taskbar to be always visible).

Here's a little C program that will toggle the hidden/shown state of the taskbar window. Note that when it's hidden it's actually gone from the screen completely (it's not in auto-hide mode).

#include <windows.h>int main() {    HWND hwnd = FindWindow("Shell_traywnd", "");    if (IsWindowVisible(hwnd))        SetWindowPos(hwnd,0,0,0,0,0,SWP_HIDEWINDOW);    else        SetWindowPos(hwnd,0,0,0,0,0,SWP_SHOWWINDOW);    return 0;}

Using SHAppBarMessage. This one toggles the autohide state.

#include <windows.h>#include <shellapi.h>// This isn't defined for me for some reason.#ifndef ABM_SETSTATE#define ABM_SETSTATE 0x0000000A#endifint main() {    APPBARDATA abd = {sizeof abd};    UINT uState = (UINT) SHAppBarMessage(ABM_GETSTATE, &abd);    LPARAM param = uState & ABS_ALWAYSONTOP;    if (uState & ABS_AUTOHIDE)        abd.lParam = param;    else        abd.lParam = ABS_AUTOHIDE | param;    SHAppBarMessage(ABM_SETSTATE, &abd);    return 0;}