What to Do If You Forget Your YouTube Username or Password
If you forget your YouTube username or password, don't panic. YouTube has your e-mail address, and you can retrieve your forgotten username or password from them. (When you first register with YouTube, jot down your username and password, especially if they’re different from those that you use regularly on other Web sites.)
Go to YouTube.com and click the Sign In link at the top-right corner of the page.
Bam — the sign in page appears.
Click either the Forgot Username link or the Forgot Password link.
Enter your username.
Enter the verification code from the multicolored text.
Be sure to copy it exactly, using uppercase or lowercase, as shown in the code.
Click the Reset My Password! button.
YouTube sends an e-mail containing your password to your registered e-mail address.
If you still can’t log in with what you’re certain is your correct username and password, it’s probably because you don’t have cookies turned on in your browser preferences. If you’re using Internet Explorer as your browser, you need to turn on cookies. In Internet Explorer, choose Tools→Internet Options and select the Privacy tab. Click the Advanced button and the set First- and Third-Party Cookies to Accept.