Unable to access UNC shares on XP Pro from Windows 7 Home Premium system - Invalid Username or Password?

Question

I'm trying to set up an old XP Pro system I was using at work as a small home file server, but my Win7 box can't access it - I get "Invalid User or Password" error - and I see the following on the XP's Security event log:

Login Failure:

Reason: Unknown user name or bad password
User Name: MediaUser
Domain: MUSICBOX
Logon Type: 3
Logon Process: NtLmSsp
Authentication Package: MICROSOFT_AUTHENTICATION_PACKAGE_V1_0
Workstation Name: BEOWULF

system stats are:

Server

name: MUSICBOX

OS: XP 32-bit SP3

Able to ping and Remote Desktop to that system from the client, but no UNC access.

Client

name: BEOWULF

OS: Win7 Home Premium 64-bit

I'm specifying a valid "MUSICBOX\MediaUser" account and password - it works for Remote Desktop, but is rejected by SMB.

MediaUser has admin rights on the XP box. MUSICBOX and BEOWULF live on the same workgroup.

Ideas?

Solution 1

Weird.

None of the above suggestions worked. I read the document linked above, and saw that MS suggested "Simple File Sharing" - well it WAS on, so I turned it OFF.

And that worked - I have full access to the shares now.

Maybe because the system was once on a domain, and now it is off of it.

Again, weird.

Solution 2

Possible cause: Win7 uses NTLMv2 authentication, while XP defaults to accepting NTLM.

On XP, run secpol.msc. Go to Security Settings → Local Policies → Security Options, find the "Network security: LAN Manager authentication level" option, and set it to the "Send NTLMv2 response only\refuse LM and NTLM" level.

(Alternatively, you could lower the authentication level on Win7 to "Send NTLM" – it's your LAN, your security requirements.)

Another post on SuperUser says the problem could be caused by large clock differences.

See also the Microsoft document Windows 7 and HomeGroup Downlevel Sharing.

Comments

[Eli]

Thanks for the suggestions, but none of them did anything helpful. I figured it out.

[Gabe]

This worked for me too, and the system at hand was never on a domain.