Windows 8 is still very much a work in progress and, with the development process still unfolding, bugs and various other issues are to be expected with the pre-release testing Builds that Microsoft puts together.
Fortunately enough, the Redmond company is providing some support designed to help early adopters fix some of the problems they come across when testing the Developer Preview Build of the OS.
KB 2616150 for example comes to resolve two glitches that testers can stumble upon immediately after log on to a machine running Windows 8 Build 8102 Milestone 3 (M3).
Update Fixes Windows 8 Developer Preview Start Screen Issues - Softpedia