fxsext32.dll error

Upon starting Outlook or sending an email, I get the following error;

"The add in C:\WINDOWS\system32\fxsext32.dll could not be installed or loaded."

I've checked, and the file indeed isn't there. I did a repair on Office and it still does this.

How can I get fix this error?

This error is quite common when you’ve upgraded from Windows XP to Windows Vista or have migrated your settings via Windows Easy Transfer although it can also appear in other scenarios. The error refers to the Fax Service Exchange Client Extensions.

Cause and first solution

Windows Vista and Windows 7 do no longer have the Windows Fax Services which is why you’ll not find this dll-file in the reported location. If you are using Windows XP, it could still be that the settings for the fax service has become corrupted.

For both cases, the way to recover is usually to rename extend.dat to .old when Outlook is closed.

Disable the add-in

If that doesn’t fix it, you can also disable the Fax Extension within Outlook. For Outlook 2003 and previous you’ll find it in Add-In Manager and in Outlook 2007 you’ll find it under Exchange Client Extensions within Trust Center. For more details about enabling and disabling add-ins, see; Enable/disable add-ins.

WinFax Pro conflict

If the error persists, it could be that you have conflicting fax software installed. It is a know issue for when you also have WinFax Pro installed on Windows XP. In that case, remove the Windows Fax Services via;
Control Panel-> Add/Remove Programs-> Add/Remove Windows Components-> disable the option: Fax Services-> Next

Note: This dll-file is offered as a download on many download sites. You really shouldn’t use the dll-files offered here as they could be the wrong version, infected or modified otherwise which could result in severe issues with your Windows or Outlook installation.