Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have two iMac computers (A & B) in one room. I have one trackpad, and I set up it up with A initially. Recently I have trouble to connect the trackpad to A. This happens when A is powered off and powered on again afterwords, the trackpad will lost its connection to A.

It seems that my trackpad would be connected another iMac B, when A is powered off. During this time, B may detect the device, and then connect to it? As a result it causes A unable to connect to the trackpad. I am not sure if there is any way to assign or set up my trackpad to only one iMac when there are more than one Mac computers in a room?

Apple's remote device has similar issue: it could remote control any Mac computers or Mac books. I remember that there is a way to set up the remote to one Mac only. Some numbers will be displayed during the setup and those numbers have to be retyped or confirmed. Not sure if this can be done for the trackpad or not. If so, what are the steps?

share|improve this question

The term that you are looking for is "pairing":

  1. Bluetooth devices like the Magic Trackpad must be paired with a computer in order to work at all.
  2. Apple Remotes are somewhat unusual in that they will work with any Mac by default, but they optionally can be paired with a specific computer.

Your Magic Trackpad apparently is paired with both computer A and computer B. You want it to be paired only with computer A. I would suggest opening Bluetooth Preferences on computer B, selecting the Magic Trackpad device, and removing the pairing by clicking on the minus sign immediately below the list of devices.

share|improve this answer
I tried this to remove it from computer B's system preference. I turned off computer A. Somehow when I touch the trackpad or move it during the time A is up, the B's sleep screen is on and I lost the trackpad from A. – Sep 22 '10 at 0:14

In my experience, the Magic Trackpad must be configured with a system, and it will only pair with that system.

In fact, it is very hard to get it paired with another system, and Apple does not provide instructions on how to switch.

I found that by removing the batteries, re-inserting the batteries, and restarting (without the first computer present), I could follow the directions and configure it for the new system as expected.

share|improve this answer

Actually a lot has happened since 2012 which looks like the last message update in this string. It is now VERY easy to pair one trackpad to multiple computers running at the same time and although this seems like a great idea, it gets really messy. To take one trackpad account off, just go into system preferences, trackpad, and click on the set up bluetooth trackpad button. It will then show you a list of authorized trackpads on that computer. Just click on the one that you DON'T want synced, and a small gray x will appear on the far right side. Click on that x to delete the pairing and then restart your system. Voila, your headache should be gone!

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .