<p>I have a web server on port 80 and port 81. IE can connect to the server on either port. This worked fine until I installed an application with a file type (.TPJ) that had a MIME type of text/xml on the client PC. At that point IE no longer opened the web site, but offered to download a file <em>serverName.TPJ</em>. The file contained the correct information from the web site.</p>

<p>I changed the installer for the application so it didn't register the MIME type. Now IE on the client PC offers to download a file with unknown file type. Note that the application has never been installed on the server PC.</p>

<p>The problem occurs with IE7. It doesn't occur with Firefox, Safari, or Chrome.</p>

<p>Does anyone know how to work around this?</p>

I found the answer. There is a left-over entry in the registry for the text/xml MIME type. It can be restored to the default value by re-registering the MSXML3.DLL.
```
```
regsvr32 msxml3.dll
```
```