Which Lightweight Linux Distribution Would Work Well on This Older PC?

If MX Linux with Xfce still feels heavy, Q4OS with the Trinity desktop or antiX are lighter alternatives. They can be useful on older systems, but they may feel less modern and require more manual setup. I’d start with a mainstream Xfce or LXQt distribution because it should offer the best balance of performance, usability, and hardware support.

You may not need to abandon KDE entirely; this hardware can run it if you keep expectations reasonable, although Xfce or LXQt will feel more responsive. For document editing and scanning, a mainstream distribution should provide the needed printer and scanner support. The main limitation will probably be web browsing, since modern browsers can use a lot of memory, so avoiding too many open tabs will matter more than the basic desktop.

Lubuntu, which uses LXQt, is another good option. It has a lighter desktop than KDE and should leave more memory available for the browser and office applications. Xfce and LXQt are probably the best starting points before considering more specialized window-manager setups.

Linux Mint with Xfce would be a straightforward choice, and Bodhi Linux is another lightweight option that should run comfortably on those specifications. Both are less demanding than a full KDE Plasma setup while still being practical for everyday desktop use.

MX Linux with Xfce is worth trying. Xfce is lightweight, popular, and should handle browsing, office work, and the printer/scanner without much trouble. If you can upgrade to 8 GB of RAM, that would help with having multiple browser tabs open, but 4 GB is usable for lighter workloads.