I'm planning to update my Win 7 to Win 10. A little worried since this computer runs FSX very well, but it seems wise, maybe, to update before Microsoft cuts off the free update. I believe they'll support Win 10 after they cease support for Win 7. My question is what should I backup before updating? I have FSX + Acceleration and only a few additional aircraft and scenery add-ons. Any advice is appreciated.

If you prefer to be safe, just copy your FSX folder to a portable dirve.

I upgraded to Windows 10 by using the Windows 10 Media Creation Tool .. http://www.thewindowsclub.com/windows-10-media-creation-tool-create-installation-media-upgrade

This went far better for me than clicking on the upgrade icon. I went from Windows 7 to Windows 10. Perfect, no loss of anything, & I had 3x FS9's & a P3D. Seemless upgrade.

Thanks for the reply.