You have Thunderbird closed while you doing all of this correct?

Matt said

You have Thunderbird closed while you doing all of this correct?

Matt said

You have Thunderbird closed while you doing all of this correct?

yes i do

So you installed Thunderbird and ran first time to create a new profile fodler. At this point it would ask you to create a ew mail account because it has none so far. Do not create a mail account because you want to use all info in backed up profile.

I'm assuming you backed up this location: C:\Users\Windows user name\AppData\Roaming\Thunderbird\Profiles\Profile name\ eg: Profile name is xxxxxxxx.default where the x's consists of letters and numbers

Make hidden files and folders visible http://kb.mozillazine.org/Show_hidden_files_and_folders

In Thunderbird Help > Troubleshooting Information click on 'show folder' This will open new window showing the default contents of the new profile folder name. These are the files you are going to over write or simply delete all of those files before pasting in the backed up files.

Close thunderbird now - this is important. Open your backed up profile folder name folder. Amongst a load of files and folders you will see 'Mail' folder - see image below as aid.

You need to copy all of those files and folders - the entire Contents of your old backup profile folder name. Paste them into the new profile folder name over writing all files and folders.

then restart Thunderbird.