I have just setup 3.1-IIS on an IIS 7.5 box, and configured sub directory multisite. Everything was fine following the instructions, except all the images and CSS links were broken. I had to change WordPress Rule 5 to get them working, from:
<rule name="WordPress Rule 5" stopProcessing="true">
<match url="^[_0-9a-zA-Z-]+/(wp-(content|admin|includes).*)" ignoreCase="false" />
<action type="Rewrite" url="{R:2}" />
</rule>
to:
<rule name="WordPress Rule 5" stopProcessing="true">
<match url="^[_0-9a-zA-Z-]+/(wp-(content|admin|includes).*)" ignoreCase="false" />
<action type="Rewrite" url="{R:1}" />
</rule>
Should the rewrite rules that are suggested by the installer be changed to reflect this, or is there something special about my setup that is incorrect?
Cheers