Several gamers report a serious lag in mouse movements when playing games after installing Windows 8.1. The problem seems to mainly affect games that don't use Microsoft's Direct Input for reading the mouse like Deus Ex: Human Revolution.
In a thread on Reddit, Mark Cranness popped up and he researched the case. Cranness is the developer of MarkC mouse fix which makes it possible to disable the acceleration which Windows adds to mouse movements. According to Cranness , Windows 8.1 has difficulties with games that don't use Microsoft's Direct Input to track mouse movements.
Games that don't use Direct Input to track mouse movements usually try to follow the position of the cursor on the screen and Cranness thinks Windows 8.1 has difficulties with that, especially with mice with high DPI values.
Cranness has no idea why the problem exists in Windows 8.1 and not in previous versions of Windows. The problems are reported for the games Deus Ex: Human Revolution, Metro 2033 and Stalker: Call of Pripyat.
Besides this issue, users also report blurry fonts on high resolution screens when using the PC version of Windows 8.1. Today we also reported problems with the update to Windows 8.1. for ARM tablet (Windows 8.1. RT).
