Accessing a Windows share with a different username

You can specify it through the command line using the net command.

net use <driveletter>: \\<server>\<sharename> /USER:<domain>\<username> <password> /PERSISTENT:YES

You can also specify different credentials using the Windows Explorer GUI. From the Tools menu select Map network drive.... On the Map Network Drive dialog window there is a checkbox for "Connect using different credentials".

Note: If you do not see the menu bar in Windows Explorer, press the ALT key to make it appear.

Yes, it is.

When you map the network share from Windows Explorer (right click on share name > Map network drive) you can use different user credentials:

You can also do it via command prompt (started as administrator):

net use [drive] [share] /user:[user] [password]

Example:

net use s: \\homesrv\share /user:vp pass123

To delete saved share usernames:

open cmd prompt type:
net use \\fileservername /del
or
net use * /del
to delete all

found @ http://www.windowsnetworking.com/kbase/WindowsTips/WindowsServer2008/AdminTips/Network/DeleteLoginCredentialsforaNetworkShare.html