Screen gets blurred and comes back after applying pressure on LCD

try in safe mode if it works fine in safe mode if it works fine issue with the video card . Uninstall and Reinstall the Video driver.// and if does not work correctly in safe mode you need to Reinstall the complete OS. and even if that does not work then you might have to replave the screen.

from your description, it appeas to be an issue with the LCD since applying pressure has effect on it. I would advise to check with compaq for warranty repairs if you still have one active. The LCD may have to be replaced for this situation. You can try to use an external monitor to check if the video controller actually works properly