If you're having trouble getting Lion to let you enable Find My Mac, you're not the only one. It seems at least a few people are running into a problem where they see the above message in the iCloud preference pane, but clicking the update button (or running System Update manually) yields no updates to install. If this describes your situation, the good news is that there is a solution -- the bad news is that it might require a little bit of patience.
Before getting too worked up over the problem, though, it's a good idea to try the simplest methods first. Go to System Preferences, go to the Security and Privacy preference pane, and click on the Privacy tab. Check to make sure that Location Services are enabled:
If that didn't do the trick, head on over to Apple's support site and download the Lion Recovery Update package manually, and install it. It's approximately 832 MB, so it may take a while to download if you're on a slower Internet connection. Once installed, reboot your Mac and go back in to the iCloud preferences (under the Internet category in System Preferences) to see if you can enable Find My Mac now. If you can check the box, you're all set!
If Find My Mac is still greyed out, however, then the problem is likely that your Mac is in need of a couple of housekeeping tasks to get things in order. This next step works best if you close any apps you have open. Open your Applications folder, then open the Utilities folder and select Disk Utility. You should be presented with a screen similar to the following:
From here, select the volume that Lion is installed on from the list on the left side of the menu as shown above. Then click the Verify Disk button on the bottom right of the window, and Disk Utility will scan the volume for any problems. The process usually takes about five minutes, but might take longer depending on the size of your hard drive.
If you're still with me at this point, I'm betting that you will probably receive a message similar to the following:
What this means is that somewhere along the line, the part of the system that keeps track of where files are stored on the hard drive recorded some information incorrectly. My guess is that this probably happened during the upgrade to Lion, and affects a specific part of the disk that is used by the recovery system. Luckily, it's not necessarily anything bad, and it's relatively easy to fix, though the process might be a bit complicated if you're unfamiliar with it, so I've outlined it below.
- Power off your Mac completely. Use the Shut Down command from the Apple menu.
- Power on your Mac, and immediately press and hold the Option key on your keyboard.
- Once you see the boot menu appear, you can release the key.
- In the boot menu, select the Recovery HD item with your mouse, or the arrow keys on your keyboard. You may need to press the Enter key to confirm the option if clicking with your mouse does not seem to work.
After a few moments, you will be presented with a screen labeled Mac OS X Utilities. This menu allows you to perform tasks like restoring a Time Machine backup or reinstalling Lion on your Mac. The option we want, however, should be the last item in the list -- Disk Utility. This will open the same screen we saw before, but this time you might notice that the Repair Disk button (in the bottom right, under the Verify Disk button we clicked last time) is now enabled. Go ahead and click the repair button, and Disk Utility will automatically find and fix any problems that are found.
Once the repair has finished, close Disk Utility, then restart your Mac by selecting Quit from the OS X Utilities menu. When your Mac is finished restarting, you'll need to head back over to the Apple support site to download the 10.7.2 Update (or download 10.7.2 Server Update if you're running Lion Server). When the download finishes, go ahead and install the update, which will require a restart when the installation has finished. Finally, you'll want to go to your Downloads folder and install the Lion Recovery HD update that we downloaded earlier.
If all went well, you should be able to go into your iCloud preferences now and enable the Find My Mac option: