A friend of mine asked me for help recently.
His new Windows 7 laptop could not authenticate to access a network share in a workgroup environment. I said “that’s going to be easy” and ran him through the usual troubleshooting – security logs, share permissions and maximum number of users, password synchronisation etc.. By the time all seemed fine and he said that he already reinstalled the OS on the laptop twice, and that all other machines are working fine with the same share and same username, I realised it’s not one of the “usual suspects”.
After enabling the correct logging procedures, we got two nice failed events in security log on the server – 680 and 529. Based on my experience, event 529 never lies. You can tell with all the certainty in the world, that when a user gets event 529, he made a mistake in his password, there is no other explaination. Well, I’ll have to revise that policy.
Password was set to “1234” for both accounts and we still got the same error. I had to go to office, so I told him to move the hard drive from the new machine to one of the older ones. I came back couple hours later and saw an IM message from him waiting for me. “DAMN, it worked.”
Reason? Failed motherboard.
Somehow it could connect to the Internet, could browse local network, but failed at authenticating a local account.
Don’t ask me how.