Visual Studio 2013 License Product Key

I solved this, without having to completely reinstall Visual Studio 2013.

For those who may come across this in the future, the following steps worked for me:

1. Run the ISO (or vs_professional.exe).

2. If you get the error below, you need to update the Windows Registry to trick the installer into thinking you still have the base version. If you don’t get this error, skip to step 3
   

   • Click the link for ‘examine the log file’ and look near the bottom of the log, for this line:
     

   • open regedit.exe and do an Edit > Find... for that GUID. In my case it was {6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}. This was found in:

     HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall{6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}

   • Edit the BundleVersion value and change it to a lower version. I changed mine from 12.0.21005.13 to 12.0.21000.13:
     
     

   • Exit the registry

3. Run the ISO (or vs_professional.exe) again. If it has a repair button like the image below, you can skip to step 4.

   

   • Otherwise you have to let the installer fix the registry. I did this by “installing” at least one feature, even though I think I already had all features (they were not detected). This took about 20 minutes.

4. Run the ISO (or vs_professional.exe) again. This time repair should be visible.

5. Click Repair and let it update your installation and apply its embedded license key. This took about 20 minutes.

Now when you run Visual Studio 2013, it should indicate that a license key was applied, under Help > Register Product:

Hope this helps somebody in the future!

Reference blog ‘story’