Microsoft has taken out the Windows 10 Mobile Build 10166 to Fast ring users in the Windows Insider Program. Users enrolled in Fast ring receive updates first; however, they also encounter more bugs in the new release.

On Friday, July 10, Microsoft confirmed the release of Build 10166, which brings small tweaks along with fixes for the bugs that were found in previous builds.

Gabe Aul, head of the Windows Insider Program, said that the new build includes a fix for the bug that causes the lock screen to appear frozen for about 10 minutes even after upgrading.

Aul revealed that the Windows 10 Mobile Build 10166 also fixes the phone unlock issue that did not allow users to unlock their handset even after tapping in the correct PIN.

"The colors in apps should now appear correctly including the titlebar in the Outlook Mail app, which is no longer orange. And we also improved reliability of app downloads and updates from the Store (which is now no longer marked as 'Beta' and the old Store has been removed)," stated Aul.

Microsoft received feedback that the size of the battery icon is very small. The latest build also brings in a bigger battery icon that allows for easy visibility.

Build 10166 may address a number of bugs found in previous releases. However, as the build is a pre-release software, it may not be free from bugs.

Microsoft announced the Windows Insider program in September 2014 along with Windows 10. Users who enroll into the program can get access to early builds of the Windows operating system. In February, Microsoft also used the Windows Insider Program for delivering a preview for the mobile phone version of Windows 10.

With the Windows Insider Program, users can identify various bugs and offer suggestions to Microsoft, which in turn can fix issues and improve the overall user experience of the platform. Microsoft has also announced that the program will continue even after the official release of Windows 10.