If you want to backup your Accounts Information, follow these steps:

1. Open the Registry Editor click on the Start button on your taskbar, then click on Run and type "regedit" and click on OK to start the regedit utility.
    
2. Expand HKEY_CURRENT_USER\Software\Microsoft\Internet Account Manager\Accounts (see picture 1).
   
   

   Picture 1

3. Select the Accounts key.
    
4. From the menu select Registry -> Export Registry File.
    
5. Select a name for the file, select the location where you want to save it, and from the Export range, make sure that Selected branch is selected.
    
6. Click Save.
    
7. If you want to restore your Accounts Information, simply Double click on the registry file, and the values will be imported to your registry (you will have to re-boot for the process to be completed).