Hide taskbar #PowerShell 

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

change $v[8]=3 to $v[8]=2 to undo