This was a note that was in the build released today As I explained in the prior post, we are making some changes to how we release builds to the Fast ring starting in 2016. The criteria we use to release builds to Windows Insiders in the Fast ring will be much closer to our criteria for flighting to our internal rings. This will allow more builds to reach Windows Insider. This also means that the builds we release to the Fast ring may include more bugs and other issues that could be slightly more painful for some people to live with. If you’d rather stick with less frequent but more stable builds, you can switch to the Slow ring by going to Settings > Update & Security > Windows Update > Advanced options and under “Get Insider Preview builds” moving the slider to the Slow ring.