Please try
1. Install connector software from http://yourservername:55000
2. Make sure username and password on the client match with username and password on server (On client Start -> Run, type Control Userpasswords2 and Hit Enter to check actual logon name)
3. Make sure time and timezone are the same on both systems
If that doesn't help you could try:
1.Start, run type secpol.msc and Hit Enter
2.Local Policies, Security Options, Network Security: LAN Manager Authentication
3.Change NTVLM2 responses only to LM and NTLM - use NTLMV2 session security if negotiated
or
1. Start, Run, type rundll32.exe keymgr.dll, KRShowKeyMgr and Hit Enter
2. Select name of your server and remove
Henk Panneman - http://www.homeserverweb.nl