Shut it down, log out, and open and entirely different browser to log in and work on it again. (might have to re-enter, or edit that W-2 to make sure it's all correct again)
Some suggest clearing cache,cookies,temp files in your current browser......but I'm not sure that really works. a Different browser commonly does.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*