A new update has been released for users of the 9879 Build obtained via the Fast Ring. So check Windows Update now folks.
http://www.winbeta.org/news/windows...uild-9879-address-bugs-and-performance-issues
ref:Roughly two weeks ago, Microsoft released Windows 10 build 9879 to Windows Insider Program participants. Those of you who were in the fast ring were able to download and install this build, but faced numerous performance issues and bugs.
Microsoft has yet to release the build for slow ring participants but today the company has released a small 2MB update (KB3019269) that 'resolves issues in Windows.' This update likely fixes a few bugs and improves performance for those who were experiencing issues with Windows 10 build 9879.
Head over to Windows Update and snag this update. Remember, it will only appear for those of you who installed Windows 10 build 9879 (fast ring). The same build is expected to be released this week for slow ring participants and will most likely include this fix as well.
http://www.winbeta.org/news/windows...uild-9879-address-bugs-and-performance-issues