To create a new profile, close Thunderbird. Launch the profile manager dialogue by entering the following into the Windows run dialogue. (Access that by pressing the Windows key and the "R" key at the same time.)
"C:\Program Files (x86)\Mozilla Thunderbird\thunderbird.exe" -p
Be sure to include the "-p" at the end of that command and the space between the close quote character and the hyphen.In that profile manager, click on "Create Profile" and follow the prompts to create the new profile and add the desired account to it. The same email account can be access from more than one profile.
See this article for more information on creating a new profile --
http://kb.mozillazine.org/Profile_Manager (Note that the Knowledgebase server seems to be down right now so you might need to wait a bit and check this link later.)
How to transfer data to the account in the new profile will depend on how the account is set up in the original profile. What protocol is used, as noted under menu path Tools->Account Settings->Server Settings->Server Type at the top right of the dialogue?