There was only SP3, Blender, VLC, and my Canon printer drivers installed at the time, and I only installed SP3 because I originally thought the lack of it was stopping the Axoloti Patcher installer from running. But that was before I asked and Mark pointed out it needs to be installed in another working environment first.
I don't think I did anything wrong to the installation, although I might have done and not realised it. It's not impossible considering the amount of messing around I've had to do with OS installations lately.
Worth it in the end though, looking forward to finally playing with it again this afternoon