I just have this question about the MS wireless comfort desktop 5000. If I'm gonna turn off my pc do I have to remove the batteries from the keyboard and mouse? both of them seems to have no on and off switch.
The batteries will drain minimally but they will drain. There would be no point though unless you leave your computer off for months at a time. It might take a year or so for the batteries to drain if you are not using the keyboard and mouse. This varies with different models though.
I guess the short answer is "No you don't have to. Why would you need to?"