Sony :: Beep Sound At Start Up And Key 'p' Is Not Working

While starting the notebook, it beeps, (short toned but continuous) and pressing Alt / Ctrl or function keys stops that noise , then system getting booted. In the login screen, in the password field automatically populated with "*" and entering correct password get into a windows.

Every key is working except 'p' and this sometimes works. But to my wonder, this key automatically getting typed in text areas frequently. it continuously prints that key whenever focus goes on the text area.