Update Your iOS Device On A New Computer Without Wiping Data

I don’t use my first-generation iPad a ton, but of course I’m going to update to the great new features in iOS 5. The problem: I’m using a different computer now than I was the last time I synced it, and iTunes issues a rather daunting warning that updating the iPad on my new laptop will wipe out everything on my iPad. They don’t offer a clear path to resolve this, it’s actually quite simple. Here’s how it works.

1. First you’ll need to authorise your new computer with the same iTunes account as you used on your previous computer. Chances are you’ve already done this, but to double check, select Store > authorise This Computer, enter your Apple ID and password, and click authorise. (Per the Apple support page, “If the iTunes Store purchases on your device were purchased with multiple accounts, you will need to authorise the computer for each one.”
2. Plug in your iDevice. When your device shows up in the iTunes sidebar, select File > Transfer Purchases from iPad (or whatever you iDevice’s name is). iTunes will move all your apps from your device to your computer.
3. Now, for good measure, right-click your device in the iTunes sidebar and select backup. (I’m not sure this is completely necessary, but it made me feel better.)
4. Now just download and apply the iOS 5 update like you normally would (that is, click the big Update button). All your apps and settings should remain in tact.

Note: The transfer purchases function will only transfer apps you’ve grabbed through the iTunes Store, which means, for example, the MP3s you’d synced to your device that you didn’t buy from Apple probably won’t make the jump. But the rest of your apps and settings should make it over. If something doesn’t make it, here’s how to download past purchases from the App Store, iBookstore and iTunes Store.