Windows 8.1 build 9600.16581

Windows 8.1 build 9600.16581 is a build of Windows 8.1 Update 1. This build was leaked on 4 January 2021 in Brazilian Portuguese only in the x64 architecture.

History
Prior to this build's leak, Russian website WZor.Net released an article that described it on 8 January 2014, where seven pictures were posted alongside other ones on Twitter.

Five days later, on 13 January, another screenshot was posted on the Polish-language CentrumWindows forum.

New features

 * Internet Explorer has been updated to version 11.0.2.

Bugs

 * In the Brazilian Portuguese leak, the Microsoft Confidential watermark uses psuedo localized text.