Numerous Network problems

You could be dealing with a Virus or other malware....... I would need some more background info: When did the problem start? Was something changed before the problem started? Anything new installed? An update?

Well, I'm running a malware scan at the minute.
The first I knew of the problem was when the user rang yesterday afternoon and told me she was having a problem with an application, I connected in and she couldn't connect to her network drives. No event log errors. I can access the network drives as a different user on that PC and she can access them logged in on a different PC.
Nothing new installed in the last few days that I'm aware of.
John.

So the error is not on the server? and it works fine from another user account?

Then the issue might just be a corrupted user profile.... you can remove it from the client computer (delete any leftovers manually from Documents and Settings) and recreate the account.

I would finish the scan....it's always good to be sure.....

Correction about the above: don't recreate the account....just have her log in after deleting the leftovers and reeboting...

To be honest, I'm not so worried about the user account at the minute. I would like to get the dcdiag errors sorted first. As you say, there seems to be some problem with DNS, but I'm not much of an expert in that field!

Lets fix what we can to eliminate variables..... DNS issues....if you really have them...can drive you nuts. I doubt at this point that you are having any since you said before that "when the user logs in from another computer she has no problems" .... for your own sake....start simple and escalate as needed.... you are doing exactly the right thing: scanning for viruses and other malware..... recreating the user account on the local client. You have already eliminated the other variables by having her log into another computer.....

You might want to try MalwareBytes Anti Malware...it's free and very good!!!

http://www.malwarebytes.org/mbam.php

THERE ARE SO MANY THINGS THAT CAN CAUSE YOUR ISSUE: So, bare with us while we troubleshoot.

You are having problems with DNS and netbios. So, I assume your going to have problems with the IP address as well.  

It looks like the SRV records are not avail for authentication. Mapping network shares through "my network places" is done via netbios.

This could be a NIC driver, NIC cable, NIC card problem. It could be your client is on the wrong subnet. It could be so many things.

In this instance USE PING from the client machine to ping the server:,
Ping Servername (this pings by netbios name)
Ping Servername.domain.name (this pings using a DNS query)
Ping xxx.xxx.xxx.xxx (to see if you can ping the server by IP address using an ARP ping)

Use ping to determine if this is a NETBIOS, DNS, or ARP problem, or a problem with all networking protocols.

Also, provide an IPconfig /all of the server as well as the client.

Make sure you also scan the client machine for virus and malware.

John.... make sure you give us some feedback before you get yourself into deeper trouble....lol....

Ok, recreating the user profile on the client PC has solved that element of the problem.
I still get the dcdiag errors, also netdiag gives the following error:
 Failed to enumerate DCs by using the browser. [ERROR_INVALID_PARAMETER]

Also, running net view on the clients gives:
System error 87 has occurred.
The parameter is incorrect.

Thanks,
John.

Look in your PDCe's event logs for errors in the 8000's, like 8021 and 8032. They should say something like, "xxxcomputer thinks it is the domain master browser, the browser service has stopped and an election has been forced."

Also have you disabled netbios???

The only bowser entries in the System log are 8015:
The browser has forced an election on network \Device\NetBT_Tcpip_{C597CBF2-FFE4-4169-B586-408BAC2A49B3} because a Windows Server (or domain master) browser is started.

and 8035:
The browser has forced an election on network \Device\NetBT_Tcpip_{C597CBF2-FFE4-4169-B586-408BAC2A49B3} because the Domain Controller (or Server) has changed its role.

Netbios is enabled. (Is assume this means the Enable... option on the WINS Tab of NIC properties?)

This is becoming a real issue now as I can use the Exchange message Tracking tool as it can't open the log share.
John.

Looks like a little role reversal. Those are the same netbios bindings. But, you can see this is changing its role from "DOMAIN MASTER" to another Domain server:

{C597CBF2-FFE4-4169-B586-408BAC2A49B3}

{C597CBF2-FFE4-4169-B586-408BAC2A49B3}

Have you recently implimented a new DC?? It looks like the holder of the five FSMO roles has changed hands and confused the browser.

Oh, I just realized this is an SBS environment, so you can't change roles.

You do have a conflict on some client, mass storage device or something trying to be domain master.

So, let's manually edit this to make sure that all who come to the network know that the SBS machine is the domain master browser.

I am going to give you an article that explains browser elections. Then, there is a registry key in there to manually define the DOMAINMASTERBROWSER. You want your SBS machine to be manually defined as the domain master browser and therefore prevent other machines from becoming domain master.

http://www.microsoft.com/resources/documentation/windowsnt/4/server/reskit/en-us/net/chptr3.mspx?mfr=true

NOTE: It is an NT4 article. The browser service has not changed since then except ONE small exception. That just happens to be the registry key you need to change. The only difference between NT4 and 2000, 2003, xp, 2008 server, vista or any other operating system is this registry key.

For NT4 the reg key is (isdomainmasterbrowser)
For Newer than NT4, the server the reg key is (isdomainmaster)

Have tried playing about with the Browser settings, but I don't think this is the issue.
If I type \\127.0.0.1\ into the run dialog I get
No network provider accepted the network path.
When I enter \\SERVERNAME,
I get an explorer window showing all the shares, but double-clicking any of them gives me the same error as above.
Any ideas? I'm pretty stumped!

It appears like you are having DNS problems with your SRV records. That is causing problems with domain authentication, as well as replication.

Check in your DNS snapin and see if there are any greyed out folders, like the MSDCS file folder under your fwd lookup zone.

If you need an example, look at this:
http://www.experts-exchange.com/Networking/Protocols/DNS/Q_24349599.html