How I upgraded from Windows 8 Release Preview to RTM

I have been dabbling and playing in Windows 8 since the first Release Candidate was out. I like it. Of course, on my laptop I have installed Classic Shell which brings back my familiar Start Menu and Desktop. Metro seems ok for tablets, but for a Keyboard and Mouse setup, it drove me nuts.

Anyway, to the meat of the post here… When the RTM was released to MSDN yesterday I downloaded the ISO. I then mounted the ISO natively in my Windows 8 Release Preview install and ran Setup. I tried the upgrade path, the selection was available. After a couple of steps I was presented with the “This is not an available upgrade path, please visit http://noupgradepathforyou for more information”.

I decided to try the Windows 7 work around for this. This means mounting the iso in Read / Write (I just copied the already mounted iso to a new folder) and then modifying /sources/cversion.ini. I changed the values of MinClient and MinServer to 7100. I then ran Setup from that folder, and my upgrade was successful.

Now, keep in mind, that this is not supported, and could end up with a catastrophic failure if some bits are not properly upgraded. But 12 hours in, and things seem stable.

16 thoughts on “How I upgraded from Windows 8 Release Preview to RTM”

  1. After downloading the preview build from Microsoft’s website, I noticed the process it would take to revert back to my current OS. This isn’t like flashing a new rom on an android device, when trying to downgrade from the Windows 8 build you cannon use a recovery partition but instead are required to use the recovery DVD.

  2. I am about ready to do this but during the install, it says “what to keep” and the only option is “nothing”

    Did you encounter this? My laptop is already domain joined and I’m remote. I know there is a risk.

    It’s not the end of the world if it doesn’t work but I’m just curious….

    I’m hoping to still be on the same domain and have the same cached credentials….


    1. I’m not a Windows administrator, so I can’t really answer this, but my guess would be if your only option is “keep nothing” then you’re going to be renaming your computer which means it would get a new SID (even if you give it the same name), and then you would have to rejoin the domain.

    2. 1. Edit (e.g. in Notepad) n:\sources\cversion.ini to read as follows:


      2. Run n:\sources\setup.exe

      This will not work if you run setup.exe from the root directory.

  3. Yes this solution did not worked for me too… I have windows 8 rtm 90 days trial version installed. and after doing fix as described here I still get same message.

  4. I have just upgraded from Consumer Preview to Windows 8 Pro using this method, and it worked like a charm. Here’s how I did it:

    I first bought the upgrade from Microsoft for the ridiculously cheap price of $14.99 (there was an offer on). I then did the download, but instead of directly upgrading, I chose to install later. My concern – as might be that of others – is where to find the installation files.

    I went to C:/Windows, then selected the option to ‘View Hidden Files.’ This will bring up the hidden folder ‘ESD.’ Within this, there is a folder called Windows, and in here, there is one called Sources. The cversion.ini file is to be found here.

    The most important thing is that after changing the file, run Setup from within this same Sources folder. Upgrade worked like a charm, keeping ALL my files, settings and applications (it did advise that Windows Mobile Device Centre wouldn’t work, so I finally did this long-overdue uninstall.)


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