A:
I've been using the Logitech Peacock Blue M310 with a 10-year old Dell laptop for past 1-1/2yrs with no problems; XP Pro 32-bit. Mouse has auto sleep mode / shutoff - that kicks in after bout 15-mins non-use. There's also off/on switch on the bottom so you can manually turn it off. This switch is also used by the Unifying software.
Got a Logitech K360 keyboard from BB bout 6-months ago, came with Unifying receiver. Downloaded the Unifying software from Logitech website. Lets me run both the mouse & keyboard off the Unifying receiver that came with the keyboard.
Please note: while the M310's DO support Logitech's Unifying technology, they come with dumb (non-Unifying) receivers.
If you need programmable buttons, check out the M510 - little bigger than M310 & comes with Unifying receiver.
Check out www.Logitech.com for more info - search by model number.
Hope that helps, good luck!