I didn't know Geoff, but I have used his website a lot in the past. It is a fountain of knowledge around everything about Windows. I hope that the Internet preserves this knowledge and with it his memory. RIP Geoff https://www.geoffchappell.com
Here's a mirror in case the original website goes down: https://geoffchappellmirror.github.io/
The ArchiveTeam folks are saving it to archive.org too.