Sometimes alt-tab doesn't work after a fresh boot into my Windows 7 Pro x64 install. Clicking on the windows in the taskbar doesn't change window either, it just makes them flash as if they need attention. The only way I can change window in this state is by minimising everything so I can see the window I want, or using that godawful Win + Tab switcher.
Has anyone else experience this problem and have any solutions? Cheers.