One of the most frequently asked questions of Linux folks is "what’s the best lightweight distro for an old PC?" The Reg FOSS desk’s current answer is Raspberry Pi Desktop. A couple of weeks ago, we covered the news of a Trixie update for the Raspberry Pi Desktop . Since then, we’ve been putting it through its paces on a couple of the oldest, slowest machines in the FOSS desk stables. It has performed splendidly. If you fancy dipping a tentative toe into Linux, but you only have a relatively old low-spec PC spare to try it on, this is ideal. This is a modern OS: it’s a 2. 6 GB download, and it uses about 8 GB of disk space when installed. It will be a bit too much for a 25-year-old PC that was intended for Windows XP, but if you have an old PC from the Windows Vista era to hand, that should do. The splash screen calls it "PiOS 6. 3," just as on Arm-based Raspberry Pi hardware. Here, though, we’re testing Raspberry Pi Desktop: the x86-64 PC edition of the Debian-based system, available at the bottom of the downloads page . Back in 2023, the PiOS got a new Debian 12-based version , which included a new Wayland-based desktop – although it still looked almost identical to the old environment, based on X11, Openbox, and LXDE. Sadly, the PC version didn’t get upgraded. Two years later – so, almost exactly a year ago – we got a Debian 13-based PiOS 6 . The PC version still didn’t get upgraded. Now the PC edition has finally caught up with Debian 13. It’s very similar to September’s PiOS 6. 3 release, complete with the option of a dock instead of a taskbar. Like the Arm version, you can use the raspi-config tool to switch between the Wayland-based labwc compositor and X. org if you prefer. There is one important difference: Raspberry Pi OS still offers 32-bit and 64-bit Arm editions, but Raspberry Pi Desktop is now x86-64 only, following Debian 13’s retirement of its x86-32 edition . The Arm editions now use kernel 6. 18 , but the PC version is still on Debian’s default kernel 6. 12. It brings the Pi’s streamlined Debian desktop to PCs, with an installer that asks few technical questions. You can do a custom installation into existing partitions if you want, but you can just click "OK" a few times and it will do almost everything for you automatically. Unlike Debian itself, there are no questions about what to download, which desktop, network installation, or anything like that. One size fits all. You get a custom desktop with a broadly Windows 95-style layout, except that the taskbar is at the top of the screen (you can move it if you want). You get a basic collection of preinstalled apps: Chromium, Firefox, a text editor, and some helpful documentation – albeit aimed at owners of real Pi hardware. At idle, it runs in a little under 450 MB of memory, and if you switch to X. org, Openbox uses about 50 MB less. The lightest variant of Ubuntu is generally agreed to be Lubuntu, but PiOS takes about half as much memory as Lubuntu 26. 04 did in our testing . We tried it on a ThinkPad X200s, released in 2008 . Ours has been upgraded with 8 GB of RAM, plus a spare 128 GB SATA SSD, but it’s on the original 1. 86 GHz Core 2 Duo SL9400 and Intel GMA4500 integrated GPU…