Windows Server R2 stop working. Cannot map network drive with my Win 7 client.

Hi to everyone.

I had a problem for quite some time time and even i tried to solved it till now unfortunately seems unreachable.

I have a 2008 R2 server which is used as SQL 2005 server. My application program shared from the server. My win 7 client  use a map network drive to access my share folder from my windows server. Suddenly my clients lost my connection. Since then i cannot connect to the folder and i got the message

Windows cannot access \\Server\Storage

Check the spelling of the name. Otherwise there might be a problem with your network. To try to identify and resolve network problems, click Diagnose.

Details: Error code: 0x80070035 The network path was not found.

I check out my share permissions, all seems ok. I also check out firewall, services, TCP/IP, share folders, really almost everything but still nothing.

Does anyone have any idea how to resolve the problem.