Hi
If you want to save battery, the battery must be removed. There is no on/off switch.
However, the battery lasts a long time and I use the keyboard every day. So you don't have to worry about the battery life in principle.
LG
Hello DAHI
Yes, this software is really not to be used. But it works without it. I connected the keyboard and mouse with the Bluetooh Tool from Windows. You can make settings for the keyboard and mouse in the control panel. This software is not necessary.