I want to upgrade my old iMac 12.1 running Snow Leopard

Ydax123,

First, backup before any upgrades.

Then, download OS X El Capitan: How to get old versions of macOS - Apple Support. Open the downloaded DMG and install the App. Then, open the "Install OS X El Capitan" App and upgrade.

Then, get macOS High Sierra: How to get old versions of macOS - Apple Support and open the "Install macOS High Sierra" App and upgrade.

Jack

You could try Internet Recovery… i think your iMac supports it

Only certain 2011 iMac models supported it, and that requires OS X 10.7 Lion or later at least. The OP is using Mac OS X Snow Leopard 10.6. Not supported in this case.

i don’t know if your iMac supports Yosemite, officially.

iMac 12,1 is an iMac (21.5-inch, Mid 2011). This supports up to macOS High Sierra, which includes prior versions, such as OS X Yosemite.

Use diskmaker x to make a usb boot stick for your mac.

Why not create a bootable installer for macOS?

You could try Internet Recovery… i think your iMac supports it… try rebooting your iMac and holding down Command ( Apple) + option key and the R keys together on your keyboard in startup… make sure your imac has an Ethernet connection… if successful you should see a spinning globe, progress bar and ‘this may take a while’ on your screen… it might be Shift+option+command+R held down together… i don’t know if your iMac supports Yosemite, officially. You might want to go for El Capitan… anyways, start out with the basics… reset smc/pmu then zap pram 3-4 times on startup.. then try either of the key combos i mentioned… otherwise, download a copy of sierra/high sierra with the link you mentioned and get a usb stick with about 8 gb capacity, mac-formatted. Use diskmaker x to make a usb boot stick for your mac. When it’s done that and you have ejected the usb stick safely, restart your iMac holding down the Option key and plug in the usb stick. This gets you to the startup manager where you can pick which disc/drive to boot from.. the usb boot drive should show up and you pick it..

hope this helps you

john b

I’d say ‘maybe, perhaps Yes’ to the SSD…..seeing as how it’s a non-Apple SSD,you’d probably have to enable TRIM. as for Clean My Mac, that’s a definite ‘no’ .. don’t download/use anything that claims to ‘clean your Mac’, or ‘fix your Mac’ …the only disadvantage with an SSD is cost. Compared to a conventional hard drive they are more expensive, but faster

john b

[Link Edited by Moderator]