signatures

Your pst-file indeed doesn’t include signatures. The signatures are being kept as separate files in the Signatures folder. You can find this folder in the following location;
  • Windows XP 
    C:\Documents and Settings\%username%\Application Data\Microsoft\Signatures
  • Windows Vista, Windows 7 and Windows 8
    C:\Users\%username%\AppData\Roaming\Microsoft\Signatures
To see this folder you must have “View hidden files and folders” enabled or you can simply copy and paste the above paths in the address bar in Explorer to directly open the folder.