VisualBox ubuntu installation error: E_FAIL (0x80004005)

I want to start ubuntu through a visual box, but this error message keeps appearing...

The virtual machine 'Ubuntu' has terminated unexpectedly during startup with exit code -1073741819 (0xc0000005). E_FAIL (0x80004005)

I did almost everything I could try, but error does not disappear... What should I do to solve this problem? (I upgraded extension files too!)