Win XP in a workgroup accessing a domain

[Marcelo]

Is there any way to initiate user sessions from a Windows XP (hooked to a
workgroup) to a domain (as you can do on Windows 95/98/ME). This machine
must belong to a workgroup, not to a domain.
Usually the access is denied even if you enter the user and password
requested.

 

[Guest]

You can communicate to members of domain from workgroup, but you can't secure the communication with domain-bound security service providers, such as Kerberos.
You can use SSL, Basic, Digest. You can even use NTLM if you add the same local account to both parties (w/same password).
-Dmitrii