Over three years Windows 10 will not be supported any longer. Your old gear might not be able to run Windows 11. So to what Operating System you should switch to?
My advise: MX Linux Xfce. See https://mxlinux.org/. It is based on debian and Ubuntu, has long term support, runs fine on old computers with at least 8.5 GB free hard disk space for installation,1 GB RAM for i386 and AMD64 architectures, a bootable CD-DVD drive or a working USB connector, and a modern i686 Intel or AMD processor.
MX Linux is stable and is easy to use. It runs faster than Windows. Another alternative OS, Google's Chrome-like Flex OS only runs on one of my old machines. And is still under development. MX Linux runs on all of them.
Installation is simple: just make a USB-stick with Rufus of the current version and off you go. You might need to tweak your BIOS a bit, if you want to run and install it on a newer machine. See https://mxlinux.org/current-release-features/
The UI looks familiar to the Windows 7 user. It has built-in documentation, like on https://mxlinux.org/manuals/. It is simple to tweak the installation to your liking. It searches for updates of the OS and installed applications automatically and warns you if any are available, but you can also start the search for them manually.
You can produce your own installation iso, so you can copy your version quickly to other machines.
You use your own user name (no spaces allowed) and can change the default root password (demo) to your own liking. You can add another user: I do not like to publish documents on-line that carry my real name hidden somewhere, so this document is written by user gergn.
With Oracle VirtualBox you can run a number of virtual machines. I have a virtual W7 64 Pro on a second internal SSD to test the daily giveaways of www[.]giveawayoftheday.com. With a virtual Windows machine you can run your favourite Windows software. As long as you have not found an adequate Linux substitute, or Wine does not support all your Windows software. See https://wine.htmlvalidator.com for tips to understand, install and use wine.
By cloning and enlarging my virtual test Windows machine, I made a second one, suitable to use as a separate virtual production Windows 7 machine. It runs stuff like Sticky Password and Microsoft 365, because they do not run under wine.
At this moment, I am testing the combination MX-21.1 Linux Xfce/VirtualBox/virtual Windows W7 64 Pro on two computers, both hardware giveaways that, according to their owner, were ready for the scrap. A HP Pro desktop and a refurbished HP Elitebook 840 G3 (originally a Windows 8 machine), that failed beyond repair a few days after the guarantee period from the refurbisher ended. After removing and refitting the original SSD it ran smoothly once again. The quite old desktop now has 10 GB RAM, as I had some old RAM lying about. It has an SSD and two HD’s. The laptop has 8 GB RAM and two SSD’s. If needed, I can add an extra 8 GB RAM.
The idea is to save old gear from the dumpster.
