Best method to run Windows OS securely

Hi,

Today I ran a standard Windows 11 OS upgrade. It failed to complete and restart then prompted to re-install Windows 11. I did this but didn't see this would wipe my current data and programs with a fresh copy of Windows and I didn't make a back-up. Silly me. Several expensive professional licences and their data were removed which will take time and money to replace.

So, my question is what is the best way to purchase and run a stable long-term Windows OS please?

Thank you