After some digging, I found enough evidence to believe that ...

    Google searches are not case sensitive - as we already knew.
    Google PR is case sensitive - as I suspected, according to web standards, URLs are case sensitive. Google and other search engines follow this rule.

There have been few reported cases of the same pages in the Google index 2 or more times, as they were linked to different cases (for example: / ABC.htm, / abc.htm, / Abc.htm) - see this post .

The root of the problem, you guessed it, is ignorance of Microsoft into the web standards. Microsoft servers are in opposition to the standard case-sensitive web where / ABC. htm is different from / abc.htm. IIS ignores the different case and allows control of the application of incorrect file.

My site is on a Windows server, the bad is the problem?
Well, it will not "downloadable" as some lammers might suggest, but there are issues to be addressed. Choice of IIS to ignore case sensitivity means that the search engines (which are case-sensitive) index the content exactly the same for different URLs. It is highly unlikely that a website would be punished for this, but definitelly can affect the ability of your website to rank well. It is especially difficult to duplicate page to rank well for terms that are going.

This is only a problem if two or more links point to the same URL in a different case. You can avoid this problem by always using lowercase tags in your link, but you can not stop other sites linking to the same URL in case - something to be done on the server in order to address this issue.

How I can fix it?
I can almost picture "Junkies URL Rewrite" jumping up and down with the solution in their hands, but as we all know, URL rewriting is a feature only available to appropriate web servers, nothing that one would expect in IIS.

A. Component Server (IIS alternative to rewriting URL)
They are not free, it is easy to install and can only be installed on your own server. The only good thing is that this would work for all files / scripts / directories on the website.
An alternative to rewriting URLs in IIS - ISAPI Rewrite .

B. Script (and some permanent redirect)
It's free, easy to install and can be installed on any server, not just yours. The only drawback is that you can only enforce the case sensitivity of the requests that are handled by this script. This means that static HTML pages, directories, images, etc. would still be exposed to this problem. HOWEVER, if with a little help from a custom 404 error page that you can do almost anything. But that is an entirely different ...

Here's how you enforce me sensitivity cases using VB Script:
Code: