On a small business network that I support (about 20 seats altogether), one of the computers cannot connect from Outlook 2010 to the hosted exchange provider. All the other computers can. The problem is not with the user's hosted exchange account. I tested by connecting successfully from one of my own office computers to his exchange provider. Worked immediately. This user recently upgraded by himself from Microsoft Office 2003 to Microsoft Office 2010. However the upgraded Outlook 2010 worked fine for over 30 days. Then one day it just stopped working. The hosted exchange company is Intermedia. I have tried to reinstall his Intermedia profile connector and tried to create a new profile. I get the same error every time I attempt this...
"The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action."
From inside Outlook I can turn on Offline Mode and turn it back off. When off, a prompt at the bottom of the screen shows Outlook trying to connect to the exchange server but reported "disconnected". I have tried a whole bunch of interventions, none of which worked. Here is a list of the things I've tried...
*turn off Windows Firewall
*turn off McAfee real time scan
*run malwarebytes scan (no viruses)
*completely uninstall Microsoft Office 2010 including uninstalling remnants of Microsoft Office 2003. Delete Office folder from Program Files. Delete "Office" Registry entries from Current User\Software and Local Machine\Software.
*numerous other attempts
The PC has normal Internet access and, as I mentioned, I scanned for viruses and found none.
I have followed Microsoft instructions in the following links with no success...
(box for "Encrypt data between Microsoft Office Outlook and Microsoft Exchange" is already checked)
"How to troubleshoot connectivity issues that are caused by RPC client protocol registry entries"
All the DLLs listed in the article appear to be present and match the version number of the O/S.
Name Type Data
ncacn_http REG_SZ rpcrt4.dll
ncacn_ip_tcp REG_SZ rpcrt4.dll
ncacn_np REG_SZ rpcrt4.dll
ncadg_ip_udp REG_SZ rpcrt4.dll
I am thinking there is some Outlook registry corruption of mismatch, possibly caused by the user's upgrade from Office 2003 to Office 2010, but at this point I cannot find the cause. Thank you for any help you can give.