Navbar: Not logged into Blogger account
If the blog happened to be in the Blogger account into which you are already logged in, then you will see this:
Navbar: Logged into Blogger account
Note that in this case, there is an extra "New Post" and "Customize" link for you to click so that you can make a new post or get into the LAYOUT (highlighted with a white circle).
If you don't see the "New Post" or "Customize" link, and you are already logged into a particular Blogger account, but don't want to log out, this is where having more than one browser will come in handy. I have 4 - Internet Explorer, Firefox (my favorite and also recommended by Blogger), Opera and Flock in my computer. You need not worry this may cause any problem to your computer unless you are using a very old computer with very limited memory. Opera used to work well with Blogger but not anymore. See Problem signing into Blogger with Opera. I now use Flock with very little problem except it does not have the Google toolbar and the built-in Google search box which I frequently use.
If you have more than one browser, then open another browser and go to
and you will get this page to either enter the URL of the missing blog or all the email addresses that you ever had, then click "Lookup":
Then check the inbox of all the email addresses you ever had to see if you have an email from Blogger which will list all the usernames that you have ever used with the email address plus instructions on how to reset the password.
If this failed, or if you actually see the username (email address) plus "New post" and "customize" in the navbar, but cannot see the blog in the Dashboard, as some blogger have complained, then I am afraid your only hope is to try to contact Blogger Support or Problem logging into Blogger or unable to see blog in Dashboard, etc.. It may be difficult to get a response from them, but if you get an automated response, make sure you reply to that email with all the details of your problem including things like operating system, browser, etc. Some bloggers have pretty good fortune in getting help that way, including one who got help the same day she was referred to the above posts. I myself have got problems solved that way a couple of times.