i dont know which virtion Thunderbird i had, recently i formated my pc and then install Thunderbird, and set the file location but all delete previous file?

'''How to tell what version you have installed:''' In Thunderbird 'Help' > 'About Thunderbird' re :''recently i formated my pc'' Formatting a computer will delete everything off your computer, so you would have needed to perform backups of everything you need to keep before you did the formatting of computer, so you could reinstall them after formatting computer. If you use a Windows OS, then your Thunderbird Profile folders would be located in this location: * C:\Users\<Windows user name>\AppData\Roaming\Thunderbird\Profiles\<Profile name>\ Appdata folder contents are hidden so you may need to make hidden files and folders visible: * http://kb.mozillazine.org/Show_hidden_files_and_folders To make a backup: You would have need to copy the Appdata\Roaming\''''Thunderbird' '''folder Or at very least the actual 'profile name' folder located in AppData\Roaming\Thunderbird\'''Profiles''' folder. Then after Formatting computer, you would need to reinstall the Thunderbird program and run it once to auto create a profile. But you would not have needed to create mail accounts as you want to use a backup. At this point you would exit Thunderbird if it is open and running. Then you would need to copy back your 'Thunderbird' folder into the 'Roaming' folder overwriting the default 'Thunderbird folder - or better still delete the default 'Thunderbird folder first and then paste in the backup 'Thunderbird folder. Then start Thunderbird.