To Remove both windows keys:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Keyboard Layout]
"Scancode Map"=hex:00,00,00,00,00,00,00,00,03,00,00,00,00,00 ,5B,E0,00,00,5C,E0,00,00,00,00

To remove left key only (this is the one I use )
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Keyboard Layout]
"Scancode Map"=hex:00,00,00,00,00,00,00,00,02,00,00,00,00,00 ,5B,E0,00,00,00,00

To remove the right key only
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Keyboard Layout]
"Scancode Map"=hex:00,00,00,00,00,00,00,00,02,00,00,00,00,00 ,5C,E0,00,00,00,00

To put the keys back on
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Keyboard Layout]
"Scancode Map"=-