the recovery server could not be contacted

Since the MrMacintosh Fix#3 involves configuring the PRAM (aka NVRAM), try a PRAM Reset (hold it for three chimes) to clear it first since maybe there is an issue with it. Try Fix#3 from MrMacintosh again. Make sure you are typing "nvram " before pasting the modified URL the second time in the Terminal app. It may be easier to follow the written instructions in the article. I'm wondering if you overlooked the "nvram " part.

So the command will look something like the following (I'm using the information in the article, but that URL may be outdated at this time, so use the URL from the install log minus the "s" in "https":

nvram  IASUCatalogURL="http://swscan.apple.com/content/catalogs/others/index-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog"

I guess you can try installing macOS 10.7 Lion from Internet Recovery Mode by using Command + Option + Shift + R. You may have problems with this as well since the older the version of macOS the more likely there will be problems. If this works, then you will need to download macOS 10.11 El Capitan using another computer & transferring the downloaded DMG file to this iMac with Lion installed. Once you upgrade to El Capitan, then you should be able to access the App Store to access the High Sierra installer.

Another option is to install OSX 10.6.3/4 from the original gray Restoration DVD which originally shipped with the Mac from the factory. Then like with the 10.7 Lion Internet Recovery Option you will need to upgrade to 10.11, then to 10.13 using the same technique. Make sure to read the El Capitan instructions since there are multiple steps to involved to extract the real installer from the DMG to the Applications folder, then running the real full installer app.

Instructions & Links for downloading various macOS installers (carefully read the instructions for El Capitan since there are multiple steps required unlike for High Sierra):

How to download and install macOS - Apple Support

Or you can use another compatible working Mac to create a bootable macOS USB installer for:

• macOS 10.13 --- generally a Mac model from Late-2009 to 2018
• macOS 10.11 --- generally a Mac model from 2007 to 2015

You can confirm the other Mac is compatible with the OS installer by using this article:

https://eshop.macsales.com/guides/Mac_OS_X_Compatibility

Macusseriain wrote:

Yes I have tried Mr Macintosh video about how to change the https to http and this did not work for me unfortunately. It seemed like a possible cause but did not fix it for me

It worked last January when I tested it. You must follow the instructions to the letter, and try again, if necessary. AFAIR resetting PRAM resets that workaround so you might also try to reset PRAM to start from a clean state. But it is possible that Apple's servers are acting up or that workaround no longer works (softwareupdate via the Terminal has been flaky lately).

You're welcome.

Sorry to know that was unhelpful.

Unfortunately, getting this old version of the OS seems to be more problematic these days. I can only suggest that if you have, or know someone who has, another Mac of the era, you might have them create a bootable installer for you, though that will still require downloading the OS from Apple's servers.

Macusseriain wrote:

Tried using the Internet Recovery Mode by using Command + Option + Shift + R but it just brought be back to the macOS Utilities screen.

Yes, that is expected. If you had looked closely you would have noticed it was offering to install macOS 10.7 Lion which is the oldest online macOS available for a Mac.

I don't ever recalling getting the original gray Restoration DVD with my iMac Mid 2010 when delivered to me.

The 2010 models were the last ones to ship with the gray Restoration DVDs. OSX 10.6 Snow Leopard was only available on DVD....Apple never released Snow Leopard as a digital download.

Happy to read you got this sorted out. Well done. 👍🏽

I suggest that once you have got the OS installed on the old iMac, get yourself a flash drive and install macOS on that as another bootable drive. A 32 GB flash should have more than enough capacity for the OS and a troubleshooting utility or two like DriveDX and SuperDuper!. Then you can just throw that bootable flash drive a drawer and have it should you need it in the future.

You may find some assistance in this article:

[FIXED] High Sierra Recovery Server Could Not Be Contacted - Mr. Macintosh

Particularly Fix #3.