I recently tripped on a need to change the Useragent string for IE11 because of an older DotNet control that I was using and was no longer in development. Again this is not my solution, but it worked for me and I thought I would share it with the world. Since it is not my solution, here is the original link [ Answer ]
<rewrite>
<rules>
<rule name="Change IE 11 User Agent to IE 10" enabled="true">
<match url="(.*)" />
<action type="None" />
<conditions>
<add input="{HTTP_USER_AGENT}" pattern=".trident\/[789]" />
</conditions>
<serverVariables>
<set name="HTTP_USER_AGENT" value="Mozilla/5.0 (compatible; MSIE 11.0; Windows NT 6.2; Trident/7.0)" />
</serverVariables>
</rule>
</rules>
</rewrite>
To make this work, you need to add the variable “HTTP_USER_AGENT” to the rewrite module in IIS. If you do not, you will be told to by the error returned in IIS. For instructions for adding the variable click the following: [ link ]
