unable to backup emails

I once managed to backup emails following below instructions.

For a successful export, follow these guidelines:

1. Set Windows Live Mail to Work offline before starting.
2. Create a temporary folder on your desktop* to contain the exported messages.
3. In the Export wizard, select the temporary folder and select All folders.**
4. When it's finished, check that the number of files in each folder within the temporary folder is one more than the number of messages in the corresponding WLMail folder.
5. Copy the temporary folder to its final destination.
   If you use a non-NTFS drive to do this, you will see a warning that some file properties will not be copied with the files. This can be ignored.

Now I am unable back up at all. I have followed others or asked the question several times before but had no success so far.

I would be so grateful, if someone could help me with this issue please?

Thanking in advance.