I just unboxed one of these and the mouse connects without any issues, but the Keyboard refuses to connect on any computer I've connected it to. I've tried everything listed on the Microsoft support page; new batteries, different computer, different location, etc. I cannot believe this combo has no sync button on the receiver or keyboard. Maybe its supposed to auto-magically sync, but so far, no communication with the keyboard whatsoever.
Its frustrating because the driver software will report connections to both the keyboard and mouse regardless of whether or not they are connected. This is my second Microsoft product and my second loser. Spent the big money on the Wireless Arc mouse and it just dropped dead after a year. Really disappointing.