I just recently lost my external 3.2 USB 1 terabyte hard drive. I was unable to recover any programs I had on it. And FS2004 was on that drive and I had some Payware Aircraft as well.
I was able to reinstall everything except for A B727-100/200 by Captain Sim But I had bought it from FSPilot shop. I kept getting a error message saying that it was unable to load FSTYPE.DLL
I wrote to FSpilotshop and was told that every one of there older disk were not able to install in windows 10 and they had nothing to offer me in its place as I wanted the B727
I managed to find a download of the same aircraft so I am back in business
So if you have any older programs on hard drives Be aware you might not be able to reinstall them in Windows 10. Of course if you have the knowledge to make the needed entries in the registry than you should be able to re load the backup.
But I would not suggest you try this unless you know what you are doing
