Every time I try to install version 526 on my windows 10 64bit computer it stalls halfway through installation and shows a message "Error opening files for writing", and I have to abort the installation. I don't rename or in any way alter, amend or tamper with the files.
It's never happened before in any previous version.
Is ccleaner running while you try to update?
run through this checklist and see what helps; https://forum.piriform.com/index.php?showtopic=5739&p=42348
I added this link to the solution post since it may be the cause the install is failing:
https://forum.piriform.com/index.php?showtopic=46763&do=findComment&comment=275147