I've been using MC since around V16 and would say that I have never had any issues whatsoever in upgrading from version to version. New versions can have little bugs, but I come here to help iron them and responses are good. I always upgrade Windows to the latest version (soon to Windows 11).
It is an extremely simple task to back-up the library to the desktop, uninstall the old version of MC, THEN install the new version and restore from the library just created. The library is backed up automatically anyway, but you ensure the very latest by doing it again manually.
Restoring the library takes just seconds or even milliseconds!
To be using Windows 7 in 2021 with third-party rubbish antivirus like Nortons is not viable and is simply asking for trouble. To expect modern software to perform under an antiquated OS with corruptive antivirus is not sensible at all. Also to be using any antivirus other than what is built into Windows 10 is unnecessary. Windows Security in non-invasive and does NOT need to be turned off (it can be tweaked optionally). There is an irrational fear of Windows 10 driven predominantly by conspiracy theorists at such places as diyudio.com. It is FANTASTIC software
I have not had a virus in well over a decade and even if I did I could restore from a sector-by-sector back-up done every week in the background by freeware (that I won't plug but is Veeam
).
The only little installation tweak that I ever do is to reset the library back-up target, because when restoring from say an MC27 library back-up to MC28, MC28 will continue to save periodic backups to the old MC27 location under My Documents (naturally - it was a setting contained in the MC27 back-up).