You can not store mail in "my documents" or a collection of other standard windows folders. That is because the data is application data not files and it is considered unsafe. Microsoft in their design of Windows about 20 years ago designated that application data be stored in the folder "application data" with the advent of Vista that became appdata. So I suggest you modify your backups to include that folder, as it contains data for most programs on your system, not just Thunderbird.

If you type %appdata% into the search box and press enter windows explorer should open and show you the physical location the environment variable appdata points to. It is by default a hidden folder and as such the content is not available to windows search.

Now as you have not really said exactly what you did to loose your data, I have no idea where you put it. If you could be more descriptive of what you actually did, perhaps someone can figure it out.

Thanks. That should help and I will try it soon.

To move my messages I went to tools/account settings/server settings/local directory/browse then clicked through to a new folder I had created in documents. I presume if I can find this as you suggest I can get them back? Or is there anything else I might need to know?

In all my years of using windows I have always disliked this storage place and until now I have successfully moved my email store to My Documents. As you know, sadly it didn't work this time!

To restore your mail change the 'Local Directory' setting back to the original path.

The original path will be the thing to find.

I assume you have other folders that have not disappeared, that you could copy from.

Thank you Matt & Christ1 for helpful replies, but sadly I'm still stuck.

%appdata% enabled me to locate the folder I need, but Thunderbird/W8 will not allow me to browse to it, nor will it allow me to type in the address manually. Presumably the security is locking me out!

Is there a way round this?

My guess is because the folder is hidden by windows. There are some instructions here http://blogs.msdn.com/b/zxue/archive/2012/03/08/win8-howto-19-show-hidden-files-folders-and-drives.aspx for showing hidden files and folders in Windows 8

Thanks again.

I have now restored the original folder, but the messages are only those from the last couple of days. All my previous saved messages are still missing.

This nightmare goes on and on! Problems like this happen quite regularly - why does Microsoft treat its customers so badly!

Now sorted, thanks.