If suddenly the share folder you access for a long, stop working, you have to erase the credentials stored to your computer. One option is to do it by CPanel > Credential Manager, believe me tried, even deleted from there, couldnt access the folder. Deleting the stored credentials by the DOS net use command made the trick!
List all stored credentials -> net use
delete all the stored credentials -> net use * /delete or delete only the entry for a share net use \\192.168.2.43\data /delete
then you have to go to mycomputer choose ‘map a drive’ (maybe ‘Connect using different credentials’ is helpful)
runas /user:myComputer\administrator “explorer /separate”</code>
origin - http://www.pipiscrew.com/?p=6269 windows-problem-accessing-share-folder