Used imac (what to do when you buy)

What version of OSX is it?

In addition to needing to know the OS version, did the seller give you install disks? Or did he tell you which OS version it originally came with?

Yes, we know there are no install disks any longer, but - it's important to know if the OS version on it now is the same that came preinstalled, because.....

if the seller upgraded the OS (to Mountain Lion for instance), he is obliged to wipe the drive and reinstall the original system as the license for any OS purchased at the app store is not transferable and is tied to the seller's Apple ID forever. That matters because, in that case, you would never be able to wipe and reinstall the OS - the app store will ask you for the original purchaser's Apple ID. And, you can't just buy the license and install it - you need to go back to the original system first.

So, please let us know what is installed - simply click on the Apple and check the version number under OS X. Then go to more info > system report and post the model identifier of the machine (something like 9,2 or 10,3), so we can help getting your machine set up.

Gritzildino,

It appears you didn't understand babowa's question.

Go to the Apple logo menu in the upper left corner of your screen, which looks like and click on About This Mac in the same spot shown as on the image below:

Next click on the More Info on the window labelled About This Mac that pops up.

Next click System report on the screen that pops up.

Next note, where on my image below the Model Identifier is. This is what babowa was looking for but on your machine.

So tell us your model identifier, and then we can tell you what should be your defacto system, and whether the seller should have given you discs to use.

Thanks, is that what is on there now?

What did it come with? If it's a 2009, it most likely came with Leopard (10.5); you will either need the install disks (you can call Apple and get replacement disks for a nominal charge by giving them your serial number) or you can get the Snow Leopard disk. You will need one or the other so you can boot from it, wipe the drive, and reinstall the system. After that, you can purchase Mountain Lion with your own Apple ID. As it is, you are, through no fault of your own, running an illegal (pirated) copy of the OS since the seller did not do what he was required to do. He was also supposed to give you the original install disks.

I'd suggest calling Apple and getting the disks - erasing and starting over is the only way you can get the OS to be associated with your own Apple ID.

What model year is this new to you used Mac? If it is not a late 2012 model or one that was made after Mountain Lion came out then it more than likely did not come with Mountain Lion Preinstalled. In that case you need to wipe the complete drive by re-partitioning the drive as one partition and reinstall the originally shippingversion of OS X.

To do that you boot the system from the Online Internet Recovery system. Hold down the Command+Option/Alt+r keys at startup. Once that loads look just under the heading "Reinstall Mac OS X". It will state what was the original version of OS X that came on that system. If by chance it is older than a 2011 model then you will need the original system discs which can be ordered from Apple at a small fee.

If it's a late 2009, it should have come with an early version of Snow leopard:

http://www.everymac.com/ultimate-mac-lookup/?search_keywords=iMac10,1

In any case, call Apple to get the install disks (give them your serial number so they can look up the machine).