It sometimes happens that after you’ve changed your Windows logon credentials, you get an error trying to connect to a network share. This error could be about you’re cached credentials not being correct and prevent you from getting access to the network share.
In order to delete the cached credentials for that particulair share, you could use the following commandline:
net use \\<servername>\<share> /delete
This will delete you cached credentials and allows you to create a new connection to the network share and be asked for your (new) credentials.