Linux

maybe try to find a linux user group near where you live. if there is one, usually you get help there, but its usually kinda different sort of help, you don't get "the solution" to get your personal whishes come true ready prepared in bite-sized piezes for easy consumption but just the help by advices or suggestions that those there can give you or directly would try out.

open source is about sharing knowledge and todays mainstream OS distributions are way more complicated than long ago so the learning curve to adjust things in ways the distribution didn't prepare (which is often a lot) might be high but always worth a try at least for the learning.

for a lightweight desktop environment that is somehow similar to the old windows98, i'ld say give XFCE a try. i think on debian/ubuntu trying out could be as easy as installing the xfce (or xfce4?) package (or maybe an xfce4-desktop-environment paclage) i don't remember the exact package name but there is one meta package that depends on all needed stuff, i did it like 4 years ago.. when installed you could try it by logging in and (your distro should have a login manager that allows this, or you'ld have to change that too) choosing xfce as desktop environment at login time, thus if you don't like it, logout again and login with the other again.

i am using xfce because it is clean, lightweight, it does its job, does not invent new unneeded features every few month (like it felt when i used kde long ago) and is adjustable enough for me. i removed the lower task bar and put the open windows components into the bar above adjustedbthat a bit, thats basically what i changed and i think it is quite similar to what win98 was (but thats not the reason for me to have it that way)

also, it is possible to change the window manager (that handles how windows are placed), the desktop manager (like task bar, application menu, maybe widges, logout buttons) and of course also one could change x.org to wayland and back without changing the other components. the login window could come from gnome project but after login one could use a complete different projects toolset.

"can" does not mean that every distro makes that an easy task. also mixing things will likely end in a fuller disk for lots of "needed" components that are maybe mostly unused. (i think i once used gnome but installed kde only for their printing dialog *lol)

when using the big distributions it is likely that no 3rd party downloads are needed to try other window managers or desktop environments, maybe search for such keywords in aptitude , apt search, or such. but new fancy stuff also often first comes from unknown 3rd party websites (or git*.com which is the same security risk as 3rd party websites) before it gets into main repositories after years (or maybe even never)

Closest thing I found was TwisterOS. […] and the fan in my case stops working. Aye-yi-yi!

maybe "TwisterOS" tries to invent air movement by software? it might be a random unrelated incident and the fan is simply broken, it might also be that it enabled some fan control and the fan would start if you only heat up the system enough which might not happen with a lightweight distro and the maybe not cpu consuming programs you use (?). "stress" is a program that could artificially create such cpu consumption for testing (but with a broken fan it might be not a good idea to actively and unnecesarily heat up the cpu, but also cpus usually have failsafe shutdown mechanisms so they dont overheat but that might be like a sudden power down so maybe expect unsaved work to just vanish) another test could be to just give the fan another power source and see what happens, and put abother fan that works in place to see if that changes something

I just installed Pop!_OS and kept the customization to a minimum. I don’t love GNOME, but I wanted Pop!_OS for the supposed better (easier?) NVIDIA support. I prefer KDE plasma, but GNOME works just fine. I would not be surprised if I ran into some issues in trying to change my DE. I do mess with Linux more sometimes, but I usually use a VM or some other machine for that. I don’t want to break my daily driver.

Don't download software from some random website.

Instead, use your package manager to install it or use something that ships with it. I would recommend Debian as its very stable and the installer gives you the option to install LXDE if you so choose. (Side note: LXDE isn't well maintained) You likely will want to enable flatpaks for newer application support but that is pretty easy to do. Just go to flathub.org and choose how to install and then Debian

Just a minor suggestion. When looking for something different than what you're currently familiar with, do so in very open minded way, hopefully no looking for clones to what you were used to, but willing to experience and learn new stuff (there's no failure, just something new that had to be learned and experienced).

I know it's easier saying than doing...

Looking for advice on giant communities is sort of hard, and in the end you won't know what works better for you if you don't try it. The open mind needs to come with some time to be able to play, and enjoy during the play, so it's not a whole series of frustrations.

On this same forum (different threads/posts/converstions) I've read very different recommendations. Even though Manjaro has been recently getting a lot of bad reputation because of letting some certs expire, it's still considered an "introductory" gnu + linux distribution. I've also read Mint is a pretty good "introductory" gnu + linux distribution as well, specially now that ubuntu has finally shown its inclination towards its snap store, rather than the good and solid dpkg + apt, which allowed it to grow on users to where it's currently at.

I myself prefer rolling release models for distributions, and being as vanilla as possible, to be closer to upstream as possible. However I dislike systemd, which is just a personal taste, so I don't have a specific recommendation. It used to be Manjaro offered openrc, but they dropped it, and the distributions I know are Artix (it has gui installers if that's considered "introduction" level distribution, but one still need to handle the configuration mismatches with upgrades as with Arch), Gentoo (I wouldn't say it's not for starters, but for sure it has its learning curve, but more importantly you need to be aware that it's a source based distribution), and Void. If you don't really care, rolling release distributions, which might have an easy ramp up might be Manjaro as mentioned, and now I believe openSUSE Tumbleweed. maybe even fedora come close... Rolling release models might come even easier for newcomers, in my opinion, since there's no need to think on what happens on major updates, but rather one needs to keep updating periodically, but hopefully the distribution helps supporting the safest and saner configurations natively so the user, and particularly newcomer to the distribution don't have to deal a lot to get such safe and sane configurations, at least to start with. And that's to me the important part to call it "introductory" distribution, easy installation might be part of it, but it's hardly the majority of it, and this is perhaps the sad part of what I like about being as vanilla as possible, some distributions even take that as a mantra for configurations, and upstream developers don't always have the safer, or the saner configurations by default. I believe Manjaro and some others take that into account to make things smoother to start with. Maintaining the distribution, keeping it up to date, being able to install stuff, has it's learning curve, no matter the tools/frameworks to do so, and it might be harder if one has to deal with how to make things work because the software doesn't work as it should (configuration required upfront), and it's not hardened enough as well so the user needs to know that and do additional configuration upfront as well.

I will let you on a little secret.

The best "support" you can get is support from upstreams directly (I'm involved in both sides of that equation). But upstreams will often only "support" you when you 1. run the latest stable version 2. the upstream source code wasn't patched willy-nilly by the packager (your distro).

So the best desktop linux experience comes with using rolling distro that gives you such packages, with Arch being the most prominent example.

The acquired knowledge that argues stability and tells you otherwise is a meme.

1. You dont download software from Websites
2. Use Lubuntu or other variants with LXQt or LXDE, dont do it yourself. They already have done the configs for you

Linux Mint has already been suggested. I recommend the XFCE edition and adding the Chicago95 theme for a pretty close Windows95/98 look. That should be a reasonable starting point.