As Windows refreshes a view that may happen.
BUT THE KEYBOARD INPUT DOES NOT SOUND NORMAL. Since you only supplied a symptom and nothing about the PC I can't offer much other than to restore the PC back to a day when it worked right.
Im wondering if anyone has ever had this issue. I am experiencing a graphic issue. Everytime i type on the keyboard, or plug/unplug in a usb my screen flashes and looks like a negative from a picture then returns to normal and i cannot figure out a cause. Anyone?

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