486
Microsoft may replace the Start button with the Copilot AI in Windows 12
(www.notebookcheck.net)
This is a most excellent place for technology news and articles.
Depends on the business really. For my last employer (~19,000 deployed PCs, lots of fussy mission critical legacy applications), 2 years would be cutting it extremely fine. For my current employer (~30 employees, nothing more complicated than standard office applications in use), you could do the upgrade in a week.
I imagine my current employer won't be worrying about upgrading before 2025.