Still on the fence about upgrading to Windows 8.1? If you're a gamer, you may want to hold off a little while longer. As PC World reports, the latest Windows release causes a number of mouse-related issues, including jittery movement and lag.
Microsoft acknowledged the issues in this Microsoft Community thread last week. Moderator Naman R explained, "The 'mouse lag' issue is actually several different issues that could vary based on the game, input methods used, etc." Three scenarios are being investigated, he says:
1. Mouse jitters (jumps forward and back) as you move it through a game – This occurs in some games because Windows 8.1 handles the games' checks for the mouse status differently.
2. Mouse movement is not to scale even after acceleration is turned off – If you have turned off acceleration to make the distance on the screen match the distance you move the mouse, that may not work correctly anymore.
3. Measured mouse Polling Rate has a lower reporting frequency than expected – If you have a gaming mouse that has a high frequency, when you test it, you may find it is reporting a lower frequency than you expect.
Those problems can affect games in different ways. One user in the community thread complained of "random mouse movements in League of Legends/DOTA," "unresponsive/inaccurate mouse movements in most FPS (including far cry 3 and BF3)," and "camera lag/jerkiness in World of Warcraft." I haven't noticed any problems myself, but I wouldn't want to be caught playing a multiplayer game like BF3 with flaky mouse input.
Happily, a fix is on the way. Naman R says Microsoft is "working to get these issues resolved as quickly as possible," though he adds, "we don’t have a date yet for the release of a fix."
In the meantime, Naman R suggests a number of workarounds, including disabling DPI scaling, turning off compatibility mode, and, for touchpads, reducing the mouse delay setting to zero. You'll find detailed instructions for these workarounds here in the Microsoft Community thread.