As we know Microsoft do NOT recommend upgrading from any pre-release version of Windows to Windows RTM. Similarly you can’t upgrade from any prerelease version of Windows 8 (including Developer, Consumer and Release Preview) to Windows 8 RTM.

You can find out more details about Windows 8 Upgrade Path here.

But we have come to know an easy workaround and in this blog post you will learn how to change minimum build requirement to upgrade from any prerelease version of Windows 8 to Windows 8 RTM.

How To:

  1. In order to do that, you need to extract Windows 8 RTM ISO to some folder. For instance, I extracted it within C:\WIN8DVD
  2. In Sources folder, find and open csversion.ini with notepad and you will see the following content.
  3. csversion-8508

    Here 8508.0 is minimum required build number for Windows 8 RTM Upgrade. That means that Windows 8 Build 8508 (an interim build) or higher can be upgraded to RTM build.

  4. So change MinClient and MinServer numbers from 8508.0 to your currently installed prelease version of Windows 8 Build.
  5. Here is the list of public builds

    Windows 8 Public Releases Build Number
    Windows 8 Developer Preview 8102
    Windows 8 Consumer Preview 8250
    Windows 8 Release Preview 8400

    For instance, I changed 8508.0 to 8400.0

    csversion-8400

  6. That’s it. Save the file and create bootable Windows 8 ISO DVD or USB stick and run setup. And you would be able to upgrade from the prelease version of Windows 8 to RTM build.

13 responses to “How to upgrade from Windows 8 Release Preview to Windows 8 RTM”

  1. Lee Marsh Avatar

    Same here, Eval version doesn’t upgrade previous Win8 RP using the above method, it still recognises the previous install. Also it won’t upgrade Win 7 pro (retail) either.

    1. Lee Marsh Avatar

      Error while trying to update Win8 RP..”Windows 8 Release Preview cannot be upgraded to Windows 8 Enterprise Evaluation. You can choose to install a new copy of Windows 8 Enterprise Evaluation instead, but this is different from an upgrade, and does not keep your files, settings, and programs. You’ll need to reinstall any programs using the original installation discs or files. To save your files before installing Windows, back them up to an external location such as a CD, DVD, or external hard drive. To install a new copy of Windows 8 Enterprise Evaluation, click the Back button in the upper left-hand corner, and select “Custom (advanced)”.”

    2. Lee Marsh Avatar

      Error while trying to update Win 7 Pro…. I’m assuming this is because the version I have is retail and not Volume Licencing….. “Windows 7 Professional cannot be upgraded to Windows 8 Enterprise Evaluation. You can choose to install a new copy of Windows 8 Enterprise Evaluation instead, but this is different from an upgrade, and does not keep your files, settings, and programs. You’ll need to reinstall any programs using the original installation discs or files. To save your files before installing Windows, back them up to an external location such as a CD, DVD, or external hard drive. To install a new copy of Windows 8 Enterprise Evaluation, click the Back button in the upper left-hand corner, and select “Custom (advanced)”.”

    3. Ramesh Kumar Avatar

      I am downloading an eval copy of Windows 8 and will revert you soon.

      1. Lee Marsh Avatar

        Did you have any better luck than me?

        1. Ramesh Kumar Avatar

          It worked and I just upgraded Windows 8 RP to Windows 8 RTM Enteprise… It seems you are trying to perform cross platform (32bit to 64bit or vice-versa) up-gradation which is not possible.

          Know more about Windows 8 upgrade path, Visit https://www.windowsvalley.com/windows-8-upgrade-path/

          1. Lee Marsh Avatar

            That’s odd… it was definitely the 90 day evaluation version you upgrade with? I was definitely using the 64bit version unless they named the files incorrectly.

            Windows8-ReleasePreview-64bit-English.iso was the RP edition I had installed and I used:

            9200.16384.WIN8_RTM.120725-1247_X64FRE_ENTERPRISE_EVAL_EN-US-HRM_CENA_X64FREE_EN-US_DV5.ISO
            To upgrade.Will re-download and try again…

            1. Ramesh Kumar Avatar

              Okay! Do one thing… Share the file called ei.cfg (finds in sources folder in ISO or DVD)

              1. Lee Marsh Avatar

                From the RTM Eval ISO:

                [EditionID]
                EnterpriseEval

                [Channel]
                eval

                [VL]
                0

          2. Lee Marsh Avatar

            This is definitely a 64bit version of the RP, I’ve just re- downloaded and installed it. Confirms its 64 bit in Control Panel. Have just tried the upgrade using the RTM evaluation iso that I just downloaded again also and it still ends with the same error. Looks like I’m going to be doing a fresh install :(

            1. Ramesh Kumar Avatar

              Well! I am playing with eval copy and hope to find some certain things by tonight.

  2. tony stew Avatar

    tried to upgrade my release preview to enterprise eval but it didn’t work. Changed both fields to 8400 and saved :(

    1. Ramesh Kumar Avatar

      Hello Tony,

      Can I have a screenshot or any error message?

Leave a Reply

Your email address will not be published.