upgrade 2010 IMac High Sierra to 64 bit

macOS High Sierra is a 64-bit operating system that can run both 32- & 64-bit apps. However, your 2010 iMac cannot be upgraded past this version.

FYI, the issue with upgrading to Catalina or later is NOT that Carslina and later will run 64-bit applications, and High Sierra won’t.

High Sierra will run both 32-bit and 64-bit applications (though it is too old to run current ones). Catalina and later will only run 64-bit applications. So all of your 32-bit applications break, and you have to find 64-bit replacements / upgrades or go without.

This is especially likely to affect games, as game developers often throw their software over the wall )do to speak), collect money, then move on to the next game without updating the old ones to remain compatible with new platforms.

If you have a lot of 32-bit applications that don’t have upgrade paths, you may want to keep an old machine around just to run them. But at some point, you have to “rip the bandage off” and make the 64-bit-only switch on your main machine so you can use recent Macs and recent versions of macOS.

You can upgrade RAM, but that would not let you run more recent versions of macOS.

You can add external USB and FireWire peripherals. (The USB ports on that machine top out at USB 2.0 speed.)

You can install Firefox 115 ESR (under Sierra or High Sierra), but even it won’t get any more security patches after next month (September).

It's a 14 yr old computer so it can still run 14 year old software. It can't be "upgraded". There's not much call for 14 year old parts.

Apple has a free recycling program, you can learn about it by clicking Apple Recycling Programs. They have a recycling for each country they sell in. As we have no idea where you are located, the link will point you to where you can find out about the program in your country.