how do i update a old airport extreme on high sierra

You might need to leave the computer turned on for several hours connected to the internet before the file will upgrade..

However you can get it yourself directly here.

http://apsu.apple.com/version.xml

That lists the different firmware for all the different airports. And you can extract the path to the firmware.

You need to know the model..

eg a Gen1 Extreme is 104

Gen2 Extreme is 105 (it has the same model number as Gen1)

Gen3 Extreme is 108

If you cannot upgrade in one step to latest.. try using 7.5.2 first.. there is a big jump then to 7.6 firmware.. so try that .. then the most recent one if you wish. I am not sure it is needed or helpful on those old airports.. if you are using them simply as WAP.

in airport utility you can only point at the file you want to use on the hard drive.

Is the windows computer not working on internet? If it has internet connection it should be able to update directly from internet firmware source.

Click on base station

Now upload firmware should have a list of different firmware. If none is available it is because the PC has not been able to pick up the details from Apple.. there is an important file which is constantly updated which contains all the different model airports and their numbers and firmware versions with locations of the file.

It is only if you pick other at the bottom of the list that you run into trouble.

We can help you a couple of different ways though.

Downloading a file is possible.

Give us the exact model of your Airport. Which Gen is it?

From that we can give you the URL to the firmware to download.

This is almost like a Catch 22

You will need to use a very old 5.x version of AirPort Utility to be able to update the old AirPort Extreme firmware as far as possible, which will likely be up to 7.5.x or a higher. That means that you will need or be able to borrow a Mac that is running an old software version like Leopard or Snow Leopard. A PC with AirPort Utility 5.6.1 for Windows would work as well.

Once you have updated the AirPort as far as possible using the old Mac or PC.......then......you will be able to use AirPort Utility running on the High Sierra Mac to update the AirPort to the current most up to date firmware......which is 7.8.1.

Unfortunately, I do not have a PC here to test, but in the past I've had no trouble at all updating the firmware on the AirPorts using a PC.

We'll have to wait for another user who has a PC handy to help out here.

BTW.. Bob must have done some serious work in the past and discovered in the old v5 airport utility a secret door to downloading all the different versions of firmware.

I have never seen this menu before (that I can recall at least) Bob may have forgotten as well .. we are getting old.

http://www.maximporges.com/2011/08/25/how-to-find-old-airport-expressextremetime-capsule-firmware/

Check back later to see if one of the PC gurus might see this post and have some ideas for you.

You are correct. I had forgotten about the firmware trick in the old version of AirPort Utility.

And yes......we are getting old.