Note: This article applies to an older version of Windows Server which is not supported by version 12+ of Project Insight. It has been found to fix a problem using the older operating system with Project Insight v12 and is provided for informational purposes only.

After applying ALL updates in a Windows Server 2008 x64 running IIS 7, you may still find that URLs without extensions result in a "page not found" error. For example, a URL ending in this will not find the page:
/pi-adm/support-request

...but one like this will work just fine.
/pi-adm/support-request.aspx

Microsoft has provided a fix to the problem using a hotfix which must be applied manually. At the time of writing this article, this fix was not found in any of the automated Windows updates as an important or optional update.

Here is the article which explains the Windows Server 2008 issue.

The following download is available to fix the problem in Windows Server 2008 x64.

The update only takes a minute, but the server does require a restart following the update.