Well, why repost this when it's available on news sites? Because I want the community here to know. This will be included in the upcoming Patch Tuesday, so you can install it then if you wish. But Microsoft has made the patch available. This is only for Windows 8.1. It should solve the mouse lag issue in Source Games and Call of Duty, and possibly even more games. Cannot hurt to install it, but to be safe, as always have a backup, at least a system restore point. Have fun, guys! Official Download Links and Details from Microsoft: 64 bit patch download: http://www.microsoft.com/en-us/download/details.aspx?id=40909 32 bit patch download: http://www.microsoft.com/en-us/download/details.aspx?id=40910 Official details via Knowledge Base Article: http://support.microsoft.com/kb/2908279 More details can be found here via Neowin.