By default, you cannot authenticate and share files to and from Mac OS X or Linux Samba due to a well known authentication method turned off by default. To enable this,

1. Goto Start—>Run and open gpedit.msc or secpol.msc (Only for Windows Vista Ultimate/Business/Enterprise Versions)

Select Continue on the User Account Control prompt. This will launch the Group Policy Object Editor for the Local Computer Policy.

2. In the Group Policy Object Editor, expand:

-> Computer Configuration
-> Windows Settings
-> Security Settings
-> Local Policies
-> Security Options

3. Open the ‘Network security: LAN Manager authentication level’ policy and change the Security Setting to:

Send LM & NTLM - use NTLMv2 session security if negotiated

4. Click the OK button to save changes, and then close the Group Policy Object Editor.

Via the Mactalk forum

Since Windows Vista Home Edition does not feature the Group Policy Editor, you may do the following to enable this feature:

1) Goto Start—>Run—> and type regedit

Select Continue on the User Account Control prompt.

2) Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Lsa

Create the following DWORD value (if it doesn’t exist):

LmCompatibilityLevel

And set its value to:1