Windows 8 : Invalid Product Key Error 0xC004F061

Windows 8 product key is not working? Are you getting 0xC004F061 error while activating the new operating system? If yes, you might be looking for a solution. Right? Lets talk about it here and try to find a solution. The error code 0xC004F061 is means your product key is invalid. Normally, that error appears when you try to use an upgrade only product key on a fresh install of Windows 8. As you know, the upgrade version of Windows 8 requires a previous version of Windows operating system. If you got a Windows 8 product key for upgrade, use it on a PC already running any of the following operating systems: Windows XP, Vista, Windows 7, Windows 8 Release Preview, Windows Developer Preview or Windows 8 Consumer Preview. Don’t try it on a fresh install of Windows 8. It won’t work and will display the invalid product key error (0xC004F061).

How to solve invalid product key error?

First be sure about the version you are installing. If you are upgrading to Windows 8, make sure that your computer is already running Windows 7, Vista or XP. If you already removed the previous operating system, you need to install that again. So, reinstall the previous version and then reinstall Windows 8. This may solve your problem.

But what if it didn’t? Or what if the same error code 0xC004F061 is appearing while you try to install & activate a full version of Windows 8 Pro? In that case, follow the advanced steps below. Note: The steps below involves use of Windows Registry. If you are not comfortable with the idea, better stay away and take help from an expert.

Troubleshoot Windows 8 invalid product key error:

1. Open Run (Shortcut: press Windows Key+R). Type regedit in the open field & press OK.
2. Windows Registry Editor will appear. Open HKEY_LOCAL_MACHINE, then SOFTWARE and Microsoft. From the long list open Windows folder. Then open CurrentVersion. From the list open Setup and go to OOBE folder. Your path should be like this: HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows/CurrentVersion/Setup/OOBE/
3. Inside OOBE folder, find the MediaBootInstall key. If the value is 1, change it to 0 (zero). Alternatively, perform a registry search for MediaBootInstall by using Find option (press Ctrl+F).
4. Close Registry Editor window.
5. Go to Run again and type CMD to open Command Prompt. You must open the CMD as administrator.
6. In the command prompt type slmgr/rearm and enter
7. Wait for the command to run and then close the window.
8. Restart your computer.
9. Go to Run and type slui.exe 3 and enter.
10. Activate Windows by entering your product key.

If your Windows 8 product key is correct, activation should work this time.

Still unable to solve the problem? You should contact Customer Service. You can visit this page for the phone number(s) of Microsoft Customer Service in your country.