Windows Server 2008 RC0 Available Now!

Windows Server 2008 RC0 is available for download today! There is a lot of excitement in the hallways here in Redmond. Since our release of Beta 3, we spent a lot of time working with IIS customers, getting feedback on our product and making sure that we could address important requests. In Windows Server 2008 RC0, available today, we added to IIS:

  • Support for IIS as an optional component on a Server Core installation option.
  • IIS7 Management console improvements specifically around UNC support (automatic validation of credential authorization and authentication for folder/path access), management of kernel-level output caching, automated recommendation for default document placement (results in performance improvements), revised Start page in the IIS7 Manager, improved “New Features Available” design, ability to turn Kerberos authentication on and off, and shared configuration support.
  • Configuration improvements including the ability to poll for changes in content configuration (web.config files) and improved shared configuration in config history
  • Core server improvements that include improved scalability for shared hosting with support for dynamic process thresholds, improved ThreadPool support and additional performance counters, a new API (flushWASTokenCache) to allow for the flushing of the token cache without restarting the IIS process, better process affinity support for application pools, and Volume Shadow Copy Service (VSS) Support.
  • Diagnostic improvements including additional performance counters (WAS_W3WP and W3SVC_W3WP), tracking of data specific to WAS and worker processes, and improved Native Code Trace support using the QuickTrace API.

If you are a Vista customer, you can download Vista SP1 Beta from Connect. If you are a Server 2008 customer, you can download RC0 from Connect, Tech Beta, MSDN, Tech Net,, and Download Center. You can also order a DVD of Windows Server 2008 RC0. Here are the links to download Windows Server RC0 from the Download Center:


    There’s a lot of great stuff in RC0. There are also two known issues that are in RC0 and we are working on addressing. These are big ones that I wanted to call out – sorry, folks, for any difficulties that this causes in your environments.

    FastCGI Module Fails to process response headers that Do Not Contain a Space Before the Header Value.
    The IIS FastCGI module, which supports PHP applications running on IIS, fails to process the response header if the header does not contain a space before the header value. An example application is Xoops. In this case, blank pages are displayed instead of serving up the PHP application pages. This behavior may occur with other PHP applications if any of the HTTP headers returned by the application do not contain a space character before the header value. Until we release our fix in the next release of Windows Server 2008, the workaround for this issue is to modify the PHP application code to return response headers that contain a space before the header value. This limitation does not occur on FastCGI on IIS6.

    Launch the IIS 6.0 MMC snap-in directly from the command line rather than adding the snap-in to the Computer Management console.
    Do not use the IIS 6.0 MMC snap-in from the Computer Management console. It may behave unexpectedly. To work around this issue, following these instructions:

    1. Install the IIS 6 snap-in from Optional Features if it has not yet been installed.
    2. Launch the IIS 6.0 MMC snap-in directly by using the following command in the Start command line: inetmgr6.exe

    As you go through the upgrade process, there are two issues that we wanted to call out, with instructions for how to work around the limitations.

    Upgrade issue from IIS6 on Windows Server 2003 to IIS7 on Windows Server 2008: ISAPI filters no longer mapped at the site level.
    If you are upgrading from IIS6 on Windows Server 2003 to IIS7 on Windows Server 2008, the ISAPI filters mapped at the site level will no longer be mapped in IIS7. Note that global ISAPI filters upgrade without any known issues, nor does it affect ISAPI extensions at all. This limitation affects filters configured at the site level. In order to restore your mapping, you will need to manually reconfigure your ISAPI filters using the IIS7 Management Console using these steps.

    1. Before upgrading IIS 6.0 to Windows Server 2008, you will need to identify all ISAPI filters defined for each web site. To find all filters defined for each site, follow these steps:
    a. From the command prompt, enter the following command where <n> is the site id of a website: Adsutil get w3svc/<n>/filters/filterloadorder
    b. This command will return a comma-delimited list of the filter names defined on that site.
    c. To get the DLL name and path for the filter enter the following command for each filter name, where
        <FilterName> indicates the name of the filter: adsutil w3svc/<n>/filters/<FilterName>/FilterPath
    d. Repeat the above steps for each web site ID defined under /w3svc/
    2. After identifying all filters, you can then upgrade the machine to Windows Server 2008 RC0.
    3. Note that after upgrading, you will need to add the ISAPI Filters to each site using the IIS7 Management Console (refer to this help topic for specific instructions). 

    Upgrade Issue from IIS6 to IIS7: Edit machine.Config before Installation of .NET Framework 3.0 and IIS7
    If you upgrade a Windows Server 2003 installation that has the.NET Framework 2.0 installed, you will be unable to install IIS7 and the .NET Framework 3.0. Setup will fail and the installation of IIS7 and the .NET framework 3.0 will roll-back. To workaround this issue, before you install IIS, you will have to edit your machine.config settings using the following steps:

    1. Using Notepad.exe, open the file located at: %SystemRoot%\Microsoft.NET\Framework\v2.0.50727\CONFIG\machine.config
    2. Add the following line to the “system.web” section group definition:
        <section name="protocols" type="System.Web.Configuration.ProtocolsSection, System.Web,
          Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" allowDefinition="MachineToWebRoot"/>
    3. If you are running on AMD64, you will need to repeat steps 2 & 3 for the file located at %SystemRoot%\Microsoft.NET\Framework64\v2.0.50727\CONFIG\machine.config



    • Are the two upgrade issues/limitations permanent or are there plans to change this in future RC versions or the shipping version?

    • We will looking to fix these issues for the next release of Windows Server 2008. Working on them now to get into our next build...

    • I want to learn this stuff. I have tried. But I don't know why I can not put the server.
      I will keep trying.

    • Is there also a VHD version that i can download?

    • Can you please clarify whether IIS 7.0 will run on Windows Server 2003 and, if so, provide a link to a URL where IIS 7.0 can be downloaded for installation on Win Server 2003? I just read a posting by Scott Guthrie from April 2007 ( where he seems to indicate that IIS 7.0 will never be able to run on Windows Server 2003. This page ( seems to indicate that IIS 7.0 can be installed and run on Win Server 2003.


    • Hi, Ambionix:
      There is not a VHD version that you can download.


    • Hi, TKent: IIS7 will not run on Windows Server 2003. IIS7 is a significant upgrade of the web server. In this blog, I talked about a couple of upgrade scenarios from Windows Server 2003 to IIS7 on Windows Server 2008. But there is no ability to run IIS7 itself on Windows Server 2003. IIS7 only runs on Windows Server 2008.


    • So will IIS 6.0 run stable on Windows Server 2008?

    • Hi,
      Are there any issues with regards to running VB6 & ASP applications on Server 08

    • Applications that run on IIS6 will also run on IIS7/WS 2008 in what we call classic mode. You should check out Mike's article on breaking changes for ASP.NET 2.0 apps on IIS7, though, to make sure that your app will not run into these situations:

      VB6 and ASP is also supported on Server 2008/IIS7.

    Comments have been disabled for this content.