PC World: A clean Windows 7 upgrade installation destroys all of your settings, requiring you to manually set up Windows all over again, reinstall all of your programs, and restore your data. It's a lot of work, but it results in a cleaner, more reliable PC. See How to Upgrade to Windows 7 for details.
Regarding providing support for Chrome on Windows 7, Google seems to have run out of patience. The most popular browser in the world will stop receiving
Microsoft no longer supports Windows 7, which means your computer is at risk. The FBI has some tips for you and your business.