Due to the implementation of the inaccurate 10 MHz software system timer, mouse movements have become inconsistent while playing games. I've found some ways to improve the situation.

https://psteamcommunity.yuanyoumao.com/groups/TheUsefulWindowsGroup/discussions/0/1643170903505065772/

HEVC, also known as H.265, is a format in which some video files are encoded.
A lot of people, including me, reported that the native decoder needed to watch these kinds of video files is missing from the system after the Windows upgrade.

Applications such as VLC will still be able to play HEVC formats.

For those interested in encoding, instead, the native HEVC encoder is NOT missing from the system.

There's no known safe solution at the moment and since the issue broke some games and applications, Microsoft is currently working to fix the issue as soon as possible.

When the user reboots a system running Build 17017.rs_prerelease.171010-1400 after a clean installation, the system may not be able to boot anymore due to a volsnap.sys Green Screen of Death on startup.

Workaround here.

The GPU tab may be missing in the Task Manager after a clean OS and drivers installation. Fix here.

Windows Insiders should now be able to just open Windows Update and retry the installation.

The update is listed as "Windows 10 Insider Preview 17017.1000 (rs_prerelease)".