This is a heck of a deal.This 2017 era system officially only supports (up to) Monterey (macOS 12) but with some major "tricks" I was able to upgrade all the way to the very latest (as of February 15, 2025) Sequoia macOS 15.3.1.The non-upgradable 8 GB RAM is actually enough and the CPU is good enough for a lot of things.However, with only a "128 GB" (actually 121 GB) non-upgradable SSD there is not normally enough space to upgrade.Trying hard enough I managed to upgrade this but it's probably not worth it for most people.WARNING!Major geek stuff comes next!The trick is to use the command line and Time Machine Utils (tmutils) to delete "snapshots" and free enough space for Sequoia to be installed. Summary (1) run tmutils listlocalsnapshots from Terminal with output redirected to a text file, (2) edit that file to have sudo tmutils deletelocalsnapshots <date of snapshot> on each line and save the file, (3) use the source command to run the commands in the file.This purges space that's not otherwise available and frees enough "disk" to do the upgrade.I then used Open Core Legacy Patcher 2.2.0 (OCLP) (free but contributions appreciated) to add the drivers for video and - critically Wi-Fi networking.My system offered the upgrade directly from Apple but I think that's because of an earlier attempt to use OLCP that was thwarted by lack of disk space enabled the upgrade once there was enough disk space.Sequoia was running after the upgrade but without working Wi-Fi and hence no network connection. I was able to find a USB ethernet adapter and get the system onto the network. Then I was able to download OCLP and run it to patch the operating system to work better.After a reboot, the video and Wi-Fi were working. I was able to add remote control both with TeamViewer Corporate and the free Chrome Remote Desktop (CRD).The attached photo is a screenshot from my main Windows 11 Pro system using CRD to access the MacBook Air and showing the "About This Mac" dialog.