So here's the issue. We run Sitecore, which does URL rewriting, and allows for something like example.com/Folder/Page.aspx to be a proper URL.
Now, "Folder" doesn't actually exist on the file system, and neither does "Page.aspx". But those URL's work, because ASP.NET does what it's supposed to.
Okay, so now say I try to go to a web page that doesn't exist like example.com/idontexist.html. This doesn't exist in on the file system, and doesn't use ASP.NET to resolve the file, so then we get a IIS7 404 Error.
Now, I want to change the 404 Error Page to a Custom Error Page, by using a URL. Say, the URL is example.com/ErrorPage.aspx. This page is actually, not a physical page, but an item in Sitecore.
In the Custom Error configuration in IIS Manager, I am trying to change the 404 Error to point to a "URL Redirect" and I'm using "/ErrorPage.aspx" as the URL redirect. When I try to then go to a URL that doesn't exist, IIS7 blows up with an error saying that it can't find /ErrorPage.aspx.
In IIS6, this isn't an issue, and everything works fine. But on IIS7, I redirect to a URL that isn't physically on the server.
Help!