Before we get started, know that most modern Macs (manufactured within the last five years or so) can run El Cap. (And if you’re looking for a comprehensive list by model, the Wikipedia page has some good info). For what it’s worth, I’ve been testing the beta for a good long time now, and I think it’s great. If you’re already running Yosemite, the El Capitan upgrade is probably a no-brainer, assuming you know that your apps are compatible (see step two below). If you’re the cautious type, though, you could always wait until 10.11.1 or 10.11.2 before taking the plunge.
Anyway, here are suggestions for what you should do before you hit that big ol’ upgrade button!
1. BACK UP. Yes, it’s in all caps. Yes, I’ve said this ten thousand times before. But if you install a major upgrade to your Mac without having a backup or three, you’re practically begging for an upsetting day. And it’s really easy to create a backup, too—if you’ve never used Time Machine before, your Mac will ask you if you’d like to use any drive you plug in as a backup device.
For more info, check out Apple’s Time Machine support pages.
So, yeah. It doesn’t matter a whole lot which backup system you’re using, but for the sake of your files, just make sure something is in place before you install El Cap (or any upgrade, for that matter). And for the love of everything that is good in this world, don’t depend on manually dragging files to an external drive, all right?
2. Verify that your apps are compatible. Hey, you know that seven-year-old photo-editing program that you use every day? Or that ancient version of Adobe’s Creative Suite that you can’t afford to upgrade? Well, it’s a great idea to confirm that whatever programs you depend on will run under 10.11 before you make the switch, or else you might have a nasty, question mark–shaped surprise waiting for you afterward.
One way to confirm compatibility is to visit the developer’s website for each program and look to see if they have any info. You can also peruse the Roaring Apps database, which has crowd-sourced reports on which apps work and which don’t under different versions of the Mac operating system.
3. Run software updates. It’s always smart to check for updates to your current system and critical apps before installing upgrades. To look for system updates and any available for apps you’ve purchased from Apple, you’ll open the App Store and click on the “Updates” tab…
…but for third-party, non–App Store programs, the process differs depending on the app. Sometimes there’ll be a “Check for Updates” option under one of the menus.
Sometimes, you’ll have to visit the developer’s website and see if a new version is available for download. If you’re not sure what version you have of a particular app, though, you might have to do a bit of sleuthing—to find out, open the program, click on its name in the upper-left corner, and choose “About [program].”
So basically, everything I suggest doing boils down to “don’t let your excitement for upgrading to El Cap keep you from preparing for it properly.” An ounce of prevention, and all that jazz. I can’t tell you the number of times I’ve had to talk folks down from the ledge when their machines wouldn’t boot after an upgrade (and they didn’t have a backup) or when an absolutely, positively critical program wouldn’t launch for them. Don’t let that be you on September 30th!