Installed Windows10 on two ASUS computers one running Win7pro the other 8.1,both installed Win10 without a problem. All files and installed programs were there after the instillation. Even my very old Paint Shop Pro 7 used on an XD computer again is working. But on the 8.1 computer my Corel Paint Shop Pro X3 can't be installed. also had to reinstall Acrocat reader on the Win7 computer to get it to work. also my installed Roxie Creator Video editing program wont work on the 8.1 machine. But works on the Win7 computer. and the 8.1 computer does not find my sony video camcorder the Win7 does find it.
But all in all I feel Windows10 ia a great move forward and good move away from Win8&8.1.