Error 0xC004C003 is a windows activation error which usually comes up when you try and activate your windows 10 after a clean install. Windows 10 is offered as a free upgrade if you are upgrading from a previous installation of Windows 7/8 or 8.1. Users who have upgraded from a previous install; have least faced the activation issue but there is a tricky part here you need to understand.
Since Windows 10 is offered as a free upgrade; there is a mechanism in place for activation, which is that it carries the information required to activate during the upgrade to easily activate Windows 10.
Now if you are doing a clean install without upgrading; it won’t carry the information from your Windows 7/8/8.1 install so you will need to buy a key because Windows 10 thinks that it is a new install.
But with these methods below and a clear understanding; you do not need to buy a key.
Activating a clean install of Windows 10
Directly installing Windows 10 by creating a boot able media without first upgrading from a previous install causes issues. If you have done this; then you will need to go back to your older / previous install (windows 7 / 8 / 8.1); activate it using the keys you have (this is usually located on the bottom or back on the Certificate of Authority) then run windows updates and re-do the upgrade.
After the upgrade; Windows 10 will activate instantly and automatically. Once that’s done; run the following script by saving it as a vbs file.
Set WshShell = CreateObject("WScript.Shell") MsgBox ConvertToKey(WshShell.RegRead("HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\DigitalProductId")) Function ConvertToKey(Key) Const KeyOffset = 52 i = 28 Chars = "BCDFGHJKMPQRTVWXY2346789" Do Cur = 0 x = 14 Do Cur = Cur * 256 Cur = Key(x + KeyOffset) + Cur Key(x + KeyOffset) = (Cur \ 24) And 255 Cur = Cur Mod 24 x = x -1 Loop While x >= 0 i = i -1 KeyOutput = Mid(Chars, Cur + 1, 1) & KeyOutput If (((29 - i) Mod 6) = 0) And (i <> -1) Then i = i -1 KeyOutput = "-" & KeyOutput End If Loop While i >= 0 ConvertToKey = KeyOutput End Function
Save the key to a safe place. It is better to save it; even though you may not need it again.
Now that it’s upgraded; and activated head over to the link below; follow the steps and do a clean install from the media creation iso: http://windows.microsoft.com/en-us/windows-10/media-creation-tool-installNote that now you’re doing a clean install; after upgrading to Windows 10.
You have now also saved the key; which you can use if needed.
To summarize this; read the note below.
There are many other methods and work arounds; however i find the one i posted easy and clean. Most users fails to understand how it all functions; technically when you do the upgrade (as a free upgrade) from a previous install; windows 10 is tied to your hardware and it uses this information to activate it self.