It is necessary to save the Shared Folders list on a file server before you migrate or re-install the Operating System. The Shared Folders list is stored at the following location in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Lanmanserver\Shares
The above registry entry includes the list of all shared folders on a computer running Windows Operating System. You can save the list in a REG file. Right Click on Shares sub-key and save it as .REG file. This is required when you are migrating a file server or re-installing the Operating Systems.