net use h: \\host\drive$ /persistent:yes

The registry setting for unencrypted passwords needs a reboot in order
to take effect.

XP Firewall app.  Start/Run/firewall.cpl

netsh firewall show/set...

Registry setting to enable clear passwords:
reate a new field EnablePlainTextPassword with a dword value of 1 in the registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkStation\Parameters\
(see http://www.chongluo.com/books/unix3/upt/ch47_03.htm )