Note: Thanks to TazTak for figuring this out and providing me with these instructions:

The Rewrite Rules that concrete5 provides in the Dashboard for enabling pretty URLs are written for the Apache Web Server. However, it's easy to get these rules to work in Windows IIS – Microsoft even provides a conversion utility to convert from Apache syntax to theirs, and that's what we'll be using.

Note: this requires IIS 7.5

1. Click on the site in IIS
2. Click on the URL Rewrite extension
3. Under InBound Rules click "Import Rules..."

4. Under "Rewrite rules:" paste:

   RewriteCond %{REQUEST_FILENAME} !-f

   RewriteCond %{REQUEST_FILENAME} !-d

   RewriteRule ^(.*)$ index.php/$1 [L]

You should see the converted rules populate.

5. Click Apply
6. Restart Concrete Website
7. Login to your Concrete5 Website.
8. Click on Dashboard tab Click on
9. Sitewide Settings Under Linking
10. Click the box to Enable Pretty URL's
11. Click the save button.

You can ignore the suggestion box as those changes were made in the above URL Rewrite step. Now you can sign out.

To confirm Pretty URLs are operating click on the site About tab at top of Home page. Address bar should only show http://YourDomainNameOrIP/about and the about page should display properly. Click refresh before you look at other issues.