Open a command window with administrator privileges. Run the following two commands in the following order. Note that they may return error messages, but let them run them anyway, then reboot, and see if the problem persists. Each of them may take several minutes to complete.
1. SFC /scannow
2. dism /Online /Cleanup-Image /RestoreHealth
After you do this, reboot and your start menu should work. You can cut and paste those commands, but if you do, do not including the numbering.
If, however, this happens after a clean installation of Windows, perhaps your keyboard is to blame.
Hi I've been struggling with these issues bout 20 days and this is whats going on.
When I press the windows key on my keyboard (corsair k70 vengance rgb) nothing happens but I also notice that at the same time the thumbnails of the programs I have currently opened disappear quickly and by the time I can click them the program doesn't come up, also alt+tab isnt working either . I've done like 8 clean installations and nothing seems to improve, aditinally normal video files flickers when this comes, it tends to vanish and everything works normally till it happens again. Right now I don't have enything but drivers installed. I'm using: Intel i7 4790, 2 8gb Kingston hyperx fury, nvidia gtx970, segate n wdc hard drives, corsair k70 rgb vengance, corsair m65 rgb.
I've also tried installing the os in different HD but nothing, even went back to w7 and I get the exact same problem.
I'd be much appreciated if u need further info pls tell me.

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