Turned on my home pc and launched Chrome from my system tray as usual last night, and got a warning message that "An administrator has installed Google Chrome on this system, and it is available for all users. The system-level Google Chrome will replace your user-level installation now."
The system tray icon disappeared. Chrome launched, but all my extensions and add-ons were gone, as were my home pages. I'm the only one with access to that pc, and I'd made no changes since turning off the pc yesterday morning. I've used Chrome on this pc (and others at home) for a couple years now - all by myself, only me. And I had not made any changes to Chrome in a couple months.
Googled this and found people got this after installing Google Earth - I hadn't done that - or something Avast does - but I don't have Avast on that pc. Nobody seemed to get an answer on why or how to stop it next time.
There was no option to say "no - don't do that!" I've got a couple other pc's that I use, and would like to prevent this from happening on them, but don't know what caused it or how to stop it. Lot of time spent reinstalling extensions and add-ons and plug-ins, needlessly.