I've done a really stupid thing and badly messed up my PC. I used netplwiz to change my user name to something closer to my real name, but as soon as I did that, I can't start any programs because I get the message above. Mine was the only account on the machine (it's also my Microsoft acct). Running netplwiz again showed no accounts. I then added a new account using Windows Power Shell. I then ran netplwiz again and gave that new account the username that I originally had, and made that account an admin. Now Windows wants me to sign out and sign back in again but I'm very worried that if i sign out I won't be able to get back in at all. Any thoughts on what to do?