Try this:
Obviously you need the Browser and Server services running. Add the 2 RPC services.
Start
Run
Type Gpedit.msc
Local computer policy
Windows settings
Secutity settings
Local policy
Security options
Select Network security; lAN manager authenticate
from drop down select Send LM & NTLM - Use NTLMv2 session security if negotiated
Reboot
If that doesnt work, try joining to workgroup instead of domain.