I'm used to seeing an "About" option (which tells me what version I'm using) when I click Help but I didn't see this on Thunderbird. How do I find the version? I'm asking because I'm trying to copy emails from Thunderbird on a Windows XP computer to Thunderbird on a Windows 8 computer and although I can copy the files, the Windows 8 Thunderbird isn't 'seeing' them. Its folder structure is very different from that of Thunderbird on the XP machine.