Today I had a user tell me that when he rebooted his computer (Vista Business SP2 x32), he could no longer connect to our Exchange 2003 server with Outlook 2007. It prompted him with the “Retry | Work Offline | Cancel” dialog. Clicking “Retry” did nothing, clicking “Work Offline” threw an error:
“The connection to the Microsoft Exchange Server is unavailable. Outlook must be online or connected to complete this action.”
The user could not connect to Exchange via Outlook 2007, nor via IE8. Firefox worked just fine after adding the https exception for our server’s self-signed certificate. So the problem wasn’t Outlook, nor was it a problem with the server. It had to be a problem with the network connection – but up to 7 system restarts still hadn’t fixed the issue. There were no proxies, IE8 was reset to manufacturer’s defaults, and the server’s domain name was put into the Trusted Sites list on IE.
After a lot of searching the internet, and talking with [Wizard] a troubleshooting step hit me: Create a new user profile and see if you can set up Outlook.
I switched-user on the computer, and tried to log into an account that was not previously set up on the computer and got:
“There are no logon servers available to service the logon request”
I immediately knew the problem was the computer’s Active Directory entry. I had seen this same error message on another computer that was recently brought to the office from my boss’s home, and had to be taken out of Active Directory, and put back in. As I go to remove the computer, I realize the computer name is exactly the same as one of the 2 computer the boss brought from home.
A couple months ago, we bought 4 identical computers, 3 of which stayed here, and the 4th one went to the boss’s home. The 3 here were named GX740-VB1, -VB2, and -VB3. Apparently the one that went to the boss’s home was also named GX740-VB2. When he brought it back last week, and wanted me to get it set up to be deployed before end-of-day Friday, I did just that.
Simultaneously, the person who sat at the original VB2 left early Friday, and shut off his computer so the pending password expiration wouldn’t lock him out over the weekend. He left at 4:00, I installed the newly finished computer at 4:30 – and there were no problems Friday. But there were now two computers on the network with the same NETBIOS name.
This morning, he rebooted his computer per his Windows Updates, and when he logged back in, he was logged into a cached profile, and his Outlook stopped working. But his shared network drives and everything else on the network cached his credentials and continued to function like normal.
Solution
If you find yourself with the “The connection to the Microsoft Exchange Server is unavailable. Outlook must be online or connected to complete this action.” Error message on Outlook, and Work Offline doesn’t let you open the Outlook client, then it’s possible that there is another computer on the network with the same NETBIOS name or same IP as you, and they have claimed ownership of that identity in Active Directory.
Change the computer name, or the IP of the offending computer, and it should fix it. You might have to drop the computer from the domain, change the computer name, and then re-add the computer to the domain as I had to.
