Kirstin McDonald,
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On the hard plastic parts you can use any kind of mild household cleanser on a soft cloth, never spray anything directly on any electronics. You can get special cleaners at the computer / electronics stores, but basically they are much different from your common all purpose cleanser. Never use anything harsh that will break down the plastic. For the soft rubber like surfaces you have to be more careful to use something very gentle like a mild liquid hand soap, just a tiny dab on a web cloth. Or try those pre-moistened hand wipes. If it is gentle enough to wipe your hands with, then it should be safe for the mouse. If the rubber has started breaking down and getting sticky, don't try to clean it, it is time to get a new mouse.
Hope this helps.
Thanks,
Gloria
Microsoft Answers Support Engineer
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