How to install and configure IIS URL Rewrite over IIS Shared Configuration Feature
Disable IIS Shared Configuration Feature temporarily before installation on each web servers
Install URL Rewrite feature on each web servers
Enable IIS Shared Configuration feature after installation
After the upgrade, you must export (or manually copy) the config files again. The install changes applicationHost.config and administration.config so the Shared Configuration files will be out of date at that point. The best way to do this is to ensure that when you turn of Shared Config that you accept the prompt to copy the config files back to \system32\inetsrv\config. Then you'll have an up to date file locally. Then after the upgrade, be sure to copy those files back again. With multiple nodes, be sure to manage all changes that occur after you turn off shared config until you turn it on again, otherwise settings could get lost. (This step copied from this web page: http://forums.iis.net/t/1166334.aspx)