Having recently set up some network storage, I came across a rather irritating problem mapping network drives in Windows XP. The basic setup procedure, as outlined here, worked perfectly on some systems, but failed to retain the stored username/password for network attached drives requiring alternative login details. The solution found, courtesy of this blog, is to map the drives using the following command (replacing U with the drive letter, and NETHOME\LOCID with the relevant UNC network location):

The necessary username/password details can then be entered and should be stored, allowing the drive to be mapped automatically when the user logs on.