Not able to install Avast Free.
Results in “Compatibiliteits Probleem”.
Installation is stopped.
What to do ?
Many thanks and greetings
Welcome to the forum. 
This should answer your question:
https://forum.avast.com/index.php?topic=156141.msg1181139#msg1181139
You’ll find the latest compatible version of Avast that works with Windows 10 Build 9926 at: https://forum.avast.com/index.php?topic=166883.msg1187702#msg1187702
Hi bob3160,
I downloaded and installed the version 2015.10.2.2214 and everything runs fine !!!
Thanks and greetings
Glad to hear that your problem has been solved.