Unable to update Safari on my old iMac with error "Safari can't open the page, because Safari can't establish a secure connection with the server."

Do I understand you to say that even with El Capitan, I cannot use Safari as the browser?

You can, it's just that it's old and will not work with many websites.

When I use that Mac I use Firefox, which is still "old" but newer than El Cap's version of Safari. To find the FF version you need, load that repository of old builds:

https://ftp.mozilla.org/pub/firefox/releases

... and look for the version I posted in my screenshot (78.15.0esr). It may be the latest one that will run. I tried a few newer ones and they didn't. If there are release notes describing system requirements I didn't investigate them.

I have also downloaded El Capitan from the website you advised. Should I try installing it over the one already installed?

I don't think it's necessary. I have a better idea. Use your download to create your own "bootable USB installer" which you can be confident is 100% legit. Instructions: Create a bootable installer for macOS - Apple Support

Just don't sell it 😄

(I had to add 1Gb memory to get it to install).

The iMac I'm using has 6 GB installed. It's plenty fast despite the fact it's also using its original spinning hard disk drive, partitioned to boot Snow Leopard, Linux, and El Cap. At one time I considered installing a SSD but it really is fast enough. Operating systems were much more efficient back then, but I did find El Cap was not happy with 4 GB. Snow Leopard ran fine with half as much.

Thanks for the update.

With OS X 10.6.8 installed, you will still have trouble loading many websites including the one with the link to download the El Capitan installer. That page won't load with High Sierra's version of Safari, leaving you no better off than when you started.

So I took the liberty of transcribing the "Where from" URL from the screenshot I posted earlier:

http://updates-http.cdn-apple.com/2019/cert/061-41424-20191024-218af9ec-cf50-4516-9011-228c78eda3d2/InstallMacOSX.dmg

Clicking it will initiate an immediate download of that .dmg file. It will resemble this (check Safari's Downloads window):

When it finishes, open it to reveal the installer package. Run the installer and you will be rewarded with a successful El Capitan installation on that eighteen year old iMac.

Then, proceed to find an El Capitan compatible version of Firefox or Chromium Legacy — your next challenge.

I just confirmed it on mine so it should work on yours. Posting from that Mac as we speak. 100% legal and free and (best of all) an interesting challenge.

Assuming it works put away that bootable USB you got from eBay. I wouldn't trust it.

That computer is likely too old for secure web browsing, but you may be able to use an alternative web browser such as Brave or Firefox. In any case, the next upgrade step is to use a physical Mac OS X 10.6 or newer install DVD.

(260429)

You will absolutely need to update that Mac to OS X "El Capitan" (the latest for that Mac) before there is any hope for any browser that will work with any website implementing recent security protocols — which is to say, nearly all of them.

Firefox ESR is the only possibility I know of, and that's only because it's what I use on that Mac. I happen to know Brave will not even install.

Considering Snow Leopard was never distributed on anything but optical media or on the hardware Apple sold at the time, whatever you downloaded is trash. Dispose of it accordingly.

Purchase a legitimate retail Snow Leopard Install DVD. They can be legally sold.

It has been gratifying to help you.

Now that you have a usable Mac, it's just going to make you want a new one though. Its performance will be several orders of magnitude greater.

Despite its limitations the fact an eighteen year old Mac can still be functional is a testament to their longevity. Macs are by far the most cost-effective computers on the planet.

I did my best to replicate what you're up against and have some information that may be helpful. Personally I think it's encouraging but my research revealed at least one additional obstacle you may need to overcome.

Briefly stated I was able to download the El Capitan .dmg file on an iMac 7,1 running OS X 10.6.8 Snow Leopard, which happens to be the closest version to the OSX 10.5.8 you have on yours. Mounting the .dmg revealed the installer package, which opened and proceeded to install El Cap without any difficulty whatsoever.

Here's the additional obstacle. There had been an interim software update that addressed the com.apple.installer.pagecontroller error you are encountering. Refer to Apple Software Installer Update 1.0 - Apple Support. As I recall (and this is going back many years) that installer update was specifically released to address that specific problem.

Now... I can certainly install OSX 10.5.8 on that Mac and do the same thing, but that will take some time that may not be justified because I have reason to believe what you're doing is 100% correct and should work... the remaining uncertainties being the fact I was running OS X 10.6.8 Snow Leopard, and you have a Windows PC which I don't.

This is the Get Info for the downloaded .dmg file:

With the exception of the created / modified dates all other information including "Where from" and its size should 100% match what you have.

You may need to find a way to install Snow Leopard on that Mac and apply the above referenced software update before you can proceed to upgrade to El Cap and have any hope of installing a browser that will be at least marginally functional with any recent website. Unfortunately getting Snow Leopard can be problematic since Apple no longer sells those discs, but you can still find them on a popular auction site at a reasonable price. They are white in color, preferably still in its original box, which bears an image of a snow leopard. Caveat Emptor as always. If you want to buy one I suggest you post here first and confirm what you're getting may be expected to work.

Anyway, that's all I have for you at the moment. Let me know how you would like to proceed — or if you would like to proceed — because as you can probably surmise this is likely to become a monumental and time-consuming effort with no practical return on investment.

You're welcome. I enjoy keeping old Macs in service as well, knowing they're functionally obsolete. That one is generally used to run Linux, which it does very well. But even Linux gets old and eventually demands newer hardware.

There is no disc for El Capitan though. The only way to get it is here: How to download and install macOS - Apple Support, and scroll down to "Use a web browser for older versions." Of course that presents a challenge if you can't even install a browser that will work, but there are ways around it.

I am reasonably certain I can point you toward a direct download link for a Firefox version that will work, if the need arises.

I have a Ebay order for a bootable flash drive for OS X 10.11 El Capitan Operating System.

You realize it's probably full of malware though, don't you? Besides, its version of Safari is too old to use with most websites (such as this one).

Cancel the order or return the flash drive in accordance with eBay's policies, one of which is that it's expressly prohibited to sell OEM software without accompanying hardware. The seller is already in violation of that policy, and is also in violation of Apple's software licensing agreement. That's their problem. Don't make it yours.

As I wrote:

There is no disc for El Capitan though. The only way to get it is here: How to download and install macOS - Apple Support, and scroll down to "Use a web browser for older versions."

Why ask for trouble when there are legitimate, free sources for both macOS and Firefox.

Does that .dmg file now reside on the iMac 7,1? If so, all you need to do is open it. If you downloaded it on a different Mac, find a way copy it to the iMac 7,1. It should work.

We cannot create a "bootable USB installer" on a Mac running an operating system earlier than El Capitan. El Cap was the first. For reference: Create a bootable installer for macOS - Apple Support

Thank you for your kind words. I am blessed to be able to help.

You can install Snow Leopard (using that DVD), which will result in OS X 10.6.3, then use Software Update which will bring it to OS X 10.6.8, which provides the App Store, and from there installing El Capitan should be a (relatively) straightforward task.

El Cap will be the end of the line for that iMac, but I'm using one now to post to this site, so it's not quite dead... yet. Not bad for an eighteen year old computer.

I recently learned of a project going by the name of "Firefox Dynasty" that may extend the life of that geriatric Mac. Read the following Discussion for the link, but from my cursory review of it it's not clear whether it can be installed on El Capitan.

How do I fix 2011 iMac booting issues with external SSD - Apple Community

I am using Firefox's "ESR" version, but its support for that OS recently ended. Sad face.

That Discussion also suggests "Chromium Legacy" but the same caveats apply.

(hat tip christopher rigby1)

Every FF version known to exist can be found in this directory:

https://ftp.mozilla.org/pub/firefox/releases

I am using the Firefox 78.15.0esr version with El Capitan at present, but I installed it years ago:

I tried a number of releases newer than that one but none of them would install. Perhaps someone else can help you find a more recent version that will work.

If you haven't already concluded that Mac is just too old to be of any practicable use, please write back and I'll try to provide some more help. No promises though... this Mac is a relic.

Stand by a little while and I'll see what I can determine. Don't have any Windows PCs though.