Windows 10 Redstone 4 build 17133.73 now rolling out for Insiders

Insiders in the Fast, Slow, and Release Preview rings are today receiving the first cumulative update for Windows 10 Redstone 4. Today's cumulative update bumps the RTM build number to 17133.73, and is packing security updates and bug fixes.

Microsoft were originally rumoured to begin rolling out the Redstone 4 update to the public today, however it appears that will not be the case now. Instead, Microsoft is rolling out cumulative updates to those already running Redstone 4 via the Insider Program, giving the release a little more time to bake before general availability, which is always a good thing.

The update refers to itself as "Cumulative Update for Windows 10 Version Next (10.0.17133.73)", likely because Microsoft still hasn't announced an official name for Redstone 4. The changelog is below, so make sure you check for updates now!

  • Addresses a PDF security issue in Microsoft Edge.
  • Addresses an issue that, in some instances, prevents Internet Explorer from identifying custom controls.
  • Security updates to Internet Explorer, Microsoft Edge, Microsoft scripting engine, Windows kernel, Microsoft graphics component, Windows Server, Windows cryptography, and Windows datacenter networking.
Zac Bowden
Senior Editor

Zac Bowden is a Senior Editor at Windows Central. Bringing you exclusive coverage into the world of Windows on PCs, tablets, phones, and more. Also an avid collector of rare Microsoft prototype devices! Keep in touch on Twitter and Threads