My problem has been with outdated programs not supported by Windows 10. Many of them.
I updated my laptop from 8.1 to 10 with no problems. Have Office 2007 that I had installed after getting the laptop with Windows 8, and it is working without a glitch. Had a hard time figuring out how to save pdf files to the hard drive but eventually figured it out after some search with Start Page.
> You are supposed to check the compatibility of your software first before upgrading. And you should upgrade your apps and programs to become more up to date.
And there it is, folks.
Old applications ALWAYS cause trouble in operating system upgrades. That's true for Windows, Mac OS X, Linux, everything.
Old software often relies on obsolete libraries, system calls, etc. Operating systems can't support back-compatibility forever.
Unfortunately, if the application vendor stopped supporting your application, you're S.O.L. and that's all she wrote, unless you want to keep an old copy of the old operating system running in a corner to run that application. But that's only a bet against time, that you will eventually lose.