If you are using basic authentication, then unfortunately, Windows 7 doesn't allow this
In Windows 7 Basic authentication cannot be persisted by the Credential Manager in Windows 7, this is new to the OS. The only way
with Basic authentication mode to reconnect is to disconnect the drive
and reconnect again, because WinHttp is not able to retrieve saved
Basic and Digest credentials. For persistent connections ensure that
an authentication scheme is selected that allowes to have persistent
credentials through a reboot. For example Kerberos for authentication
or certificate based authentication will work.
If you are using integrated windows auth, then there is a reg setting you need to enable to allow it to work.
Add the name of the Server there