The format for the specified network name is invalid

[chicagotech]

Case 1: I tried many ways to join the Vista PC to my Windows Server 2003 domain, but kept getting the same error. After I changed the primary DNS to the IP address of the DC, I was successful.

Case 2: When I tried to add my Vista laptop to domain using the hostname nc4010, I receive "The format for the specified network name is invalid". After I tried FQDN, nc4010.chicagotech.net, it works.

Case 3: My case is reverse. The FDQN doesn't work. I must use hostname to join the domain.

[chicagotech]

Based on my research, the issue may occur if the domain name resolution is
not successful.

Do you type the FQDN (The full DNS name) or NetBIOS name of the domain when
trying to join the domain?

According to the information you provided, you have set the IP address of
the DC as the primary DNS server. Please type the FQDN of the domain (For
example: domainname.com) to test the issue.

If it fails, please type the NetBIOS name of the domain (For example:
domainname) instead.

I understand you have disabled the firewall and virus scan programs. Please
make sure the Windows Firewall is also turned off.

In addition, please use the NSLOOKUP utility to verify if the domain name
can be resolved by the client:

1. Click Start, click Run, type cmd and click OK.
2. Type the following command and press Enter:

nslookup domainname

Then, check the result.

3. Type exit and press Enter.
4. Quit the Command Prompt window.

The issue can also be related to user authentication. If the issue
persists, please set Kerberos to use TCP to test the issue:

1. Start the Registry Editor.
2. Add the following value:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa\Kerberos\Parameters

Name: MaxPacketSize
Type: REG_DWORD
Data: 1

Note: If the Parameters key does not exist, create it now.

3. Quit the Registry Editor.

For detailed information, please refer to the following Knowledge Base
article:

How to force Kerberos to use TCP instead of UDP in Windows Server 2003, in
Windows XP, and in Windows 2000
http://support.microsoft.com/kb/244474

Then, restart the computer to test the issue.

[chicagotech]

In our case we receive this message when running logon script in one of Vista computers (others are fine): "Loading script failed (The format of the specified network name is invalid).

We compared all Visat computers and found the problematic Vista doesn't have SP1. After installing the SP1, it works fine.