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fuzzyjez

macrumors newbie
Original poster
Sep 14, 2006
1
0
Hi all, I'm revisiting an old 27"iMac - a couple of years ago I did a reinstall back to the original Dvds (running Lion) thinking it would run smoother & faster etc. Realising I was heavily restricted in most basic 21st century activities in this prehistoric place I have tried in vain to upgrade to El Capitan from which it seems, I can continue to upgrade to high Sierra and beyond. I'm just having trouble actually getting to the El Capitan stage; I can't find a reliable source of this OS anywhere. Does it still exist on the web or is there a work around?? Many thanks!
 

mdgm

macrumors 68000
Nov 2, 2010
1,665
406
Depending how old the machine is it may have Internet Recovery. Installing a very old version of Mac OS you'll likely need to set the date back to before the certificate expired for the installation to work.

If you had 10.12.4 (or later) installed at some point on a Mac that supports Internet Recovery the best option if going down the internet recovery route would be to do Option + Command + R to install the latest Mac OS still available for your machine. See https://support.apple.com/en-au/HT204904

The biggest thing you can do to make it run smoother and faster is to boot it off a SSD if you are not already. An SSD makes an old machine feel a lot newer. It won't be as fast as a new machine but most users aren't going to be pushing CPU and RAM to their limits. The bottleneck is the slow HDD.

An easier upgrade is to increase the RAM. These days 8GB (or more) is a good amount to have. It depends how old your machine is how much it will take.

For external booting, Thunderbolt, then USB3, then FW800 then USB2. Depending how old the machine is it will only have some of those options available.

I'm booting a 21.5" 2011 iMac off a TB3 SSD. iMac -> TB (1/2) cable -> Apple TB2 to TB3 adapter -> TB3 dock -> TB3 NVMe drive. This isn't cheap but is faster than a single internal SATA III SSD would be.
 
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Bray93

macrumors newbie
Nov 14, 2020
16
12
As posted above, you can find an El Capitan DMG available for download directly from Apple here:

Download an old version of OS X

Since you restored your iMac to Lion, I'm guessing your device is around the 2009-2010 era. You should be able to download the DMG above and simply upgrade.

If there is nothing on the iMac except the OS at the moment, I would download the latest supported version (High Sierra) and create a bootable USB. This will save you downloading 2-3 different versions of MacOS and some time installing them over the top of each other. Instructions directly from Apple on how to create a bootable USB installer:

How to create a bootable installer for MacOS
 
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mdgm

macrumors 68000
Nov 2, 2010
1,665
406
If it came with Lion originally if bought new from Apple it's probably a 2011. The 2011 iMac originally came with Snow Leopard, but when Lion was released Apple changed production to ship it with Lion. However, I don't know if Apple ever shipped DVDs for Lion. Once they switched to Lion, a firmware update provided Internet Recovery to 2011 Macs so DVDs were no longer needed.

So a DVD being used may suggest a 2009-2010 era machine perhaps.
 

MBAir2010

macrumors 604
May 30, 2018
6,684
6,135
there
I remember downloading Lion OSX the exact release date which was in mid august 2011 for $19.99,
and the download is free if the mac original OSX was Lion or Mountain Lion.
 
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