iMac 20 OS X support

A1224 is shared by several models with differing OS limitations. That's why rkaufmann asked for more info. If you are running OS10.6.8, "About this Mac" will NOT show your exact model name--that started with OS 10.7. For you, About this Mac will give this screen:

You need one more step. Click the "More Info..." button at the bottom. That will launch System Profiler, whose opening screen with what we need looks like this:

Note that I've used a red arrow to indicate a code in the second line. That is a precise identifier. On your computer, what is that code?

For security reasons please do not post a serial number.

Your machine is too old to update to Sierra (10.12.6) too. Sierra requires a late 2009 or later iMac. That version of Mac OS your machine can upgrade to is 10.11.x

Considering your machine is over 10 years old, you may want to consider buying a more up-to-date iMac.

Please carefully read How to download macOS High Sierra - Apple Support. specifically the section where it notes which iMacs are supported. If you are not sure of the year of your iMac click the Apple symbol in the upper left of the display and select About this Mac and it will indicate what year iMac it is.

However to answer your question more directly, no your iMac is simply too old. You can upgrade it to 10.11.x though.

That's an early 2008 model. In theory, it can go as high as El-Cap... macOS 10.11. In practice I wouldn't want to try it. Even if you were to max out the RAM (4GB according to Apple, 6 with a special kit you may still be able to get) and replace the rotational hard drive with an SSD, it's going to be slow.

It's almost 10 years old. Before you sink more money into it, consider replacing it with something newer.

Your only choice for that machine at this point is El-Capitan. Yosemite is no longer available.

Rickyleroy wrote:

What last OSX Can I update to ?

As mentioned earlier, 10.11.x. Use the Mac App store to do this. However, please remember before doing a major upgrade ensure all your apps will run on that version of Mac OS and also ALWAYS ensure you have a backup just in case of upgrade problems. Your machine is quite old!

If any of your apps are PPC based they will not run on versions of Mac OS beyond 10.6.8. Please read the following article.

http://osxdaily.com/2011/07/15/how-to-check-if-applications-are-incompatible-wit h-mac-os-x-lion/

Rickyleroy wrote:

I saved to usb device El Capitan setup so I think it's possible to make it for Yosemite too?

Sure, it's possible. What it is not is legal for someone else to give you an installer for Yosemite. If you didn't already 'purchase' Yosemite from the Mac App Store, then you can not obtain a legal license for it any more. Someone else can not transfer their license to you. That's not how software licensing works.

It's not possible for someone to "give you" a legal copy of Yosemite.

You might be able to have it installed for you by Apple at the genius bar of your local Apple Store. Make an appointment, take your machine in, and explain the problem.

If the ONLY reason you're doing this is so you can back up your phone, you'd be better off to sign up for additional iCloud storage if you need it and use iCloud backups instead.

It's not a matter of money. Just because it was made available at no charge does NOT mean it can be traded among individuals. That's not how it works.

It is permanently tied to the Apple ID used to purchase it. You can't use a copy of the OS that someone else downloaded from the app store.

You could give the installer you made to someone else and they could install it using their ID IF, AND ONLY IF they had previously purchased it using their ID. If they did not, they can not install it using their ID because they don't own it.