Go to your Google Account. On the left navigation panel, select Security . On the Your devices panel, select Manage all devices. You'll see devices where you're currently signed in to your Google Account or have been in the last few weeks.

Go to http://accounts.google.com/signin/usernamerecovery and enter any email accounts or phone numbers that you've had for a while and which may have been used as recovery info. The “find your email” page can help you locate any forgotten Google accounts.

Type in your username and password. Once you've opened the web address of your email provider, you will see a login page. Enter your email account's credentials (username and password) in the text fields provided. If you forgot your password, you can usually click the "Forgot Password?" link to reset it.