I tried twice to download the ISO but wound up with truncated files. A 5GB download takes ages with my not much more than 2Mbps connection so I didn't bother trying again.

I've not been that impressed with the Assistant method even with a PC MS says is OK though. I've been through this process twice with my PC (I decided to start afresh with Win 9 pro I bought rather than continue with the Win 9 Home version I'd taken by using a disk from another PC) and on both occasions, the upgrade failed at around 70% with some cryptic error message.

The first time, I thought it was because the Nvidia graphics card would not support Direct X 12 but, second time round, I had a compatible Nvidia graphics card with the latest drivers installed and it still failed. My best guess is that my system needs the drivers for the built Radeon grapics installed (and perhaps having that card in use - both my succesful attempts had this) before the upgrade will go throuh.

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One a diferent sujbject, triggered by a question Dave asked... I may find it an expensive mistake but I want to see how I get on with using Win 11 as the main OS on my desktop PC.

Most of the programs I use are cross platform and I can still do any server admin I might need via ssh. I'm not a great fan of dual boot in that I tend only to use the other OS when stuck and don't want to try the route of Win 11 on a virtual server or see if I can get more coplicatd programs running under wine. One program I do want to have a play with is the free for personal use version of Fusion 360 and there may be other examples of programs without Linux versions I'd like to try.

Whatever I wind up settling for, the rest of the system (which includes mums PC and dad's laptop) will remain on Linux, in my case both OpenSuse and Raspberry Pi OS.