How to Backup and Restore Signatures in Outlook 2013
You’ve created several signatures that you use for various types of emails. Then, you get a new machine and have to set up Windows and all your programs again. However, you can easily preserve your signatures in Outlook and restore them to the new machine.
Signatures are not stored in the .pst file Outlook uses for email messages. They are stored in the following location:
There is an easy way to open this location from within Outlook. Click the File tab.
On the Account Information screen, click Options in the list of menu items on the left.
Click Mail in the list of menu items on the left side of the Outlook Options dialog box.
In the Compose messages section, press Ctrl while clicking on the Signatures button.
The Signatures folder opens in Windows Explorer. To backup your signatures, simply copy all the files in this folder to another location.
To restore your signatures, copy them from your backup location back into the C:\Users\%username%\AppData\Roaming\Microsoft\Signatures location. The next time you open Outlook, your saved signatures will be available. If you had signatures selected as default signatures for new emails and for replies and forwards, you’ll have to define those again.
NOTE: Each signature you create in Outlook exists in three formats: Plain Text (.txt), HTML (.htm), and Rich Text (.rtf). You need to backup all these formats for each signature.
Please refer to link: http://www.howtogeek.com/175632/how-to-backup-and-restore-signatures-in-outlook-2013/