XP claims my log in and/or password are incorrect

[viper390th]

I am posting from my phone since XP claims my login info is incorrect. I logged in this morning just fine but when I got home, it says "Please make sure user name and domain are correct then type password." I know for 100% they are correct. I've tried the 'administrator' in safe mode, run hard drive diagnostic and even tried throwing the keyboard. Nothing working! Any ideas?

 

[Tmagic650]

You tube demonstration:

http://www.youtube.com/watch?v=J-z_lH0l44I&feature=related

I have used this technique