Am occasionally having an occurence where I press Start, Start Screen then appears. I begin typing to search, if no results are found there's nothing to select and the search screen remains 'on top' whether I alt-tab, go to Start again, or even press CTRL, ALT + DEL.

When I go to Start, the start screen appears again. As soon as I click on anything that requires the desktop, i.e. Excel or Word, the search screen appears again. The only way I can escape the search screen being on top of everything is to log out.

This is on three different Windows 8 Systems.