I have a Dell Latitude E6520 laptop that I decided to reinstall Windows 7 on. Before wiping the old installation, I grabbed info about the product keys from the registry using the NirSoft ProduKey tool (I thought this would be enough). One of the entries was "Windows 7 Professional" and it gave me a product ID and product key. I still have these.

So I wiped the old install and installed afresh from my Windows 7 retail ISO, selecting Windows 7 Professional to install. All went well until it came to product activation. When I try to activate Windows with that same product key, I get the error:

A problem occurred when Windows tried to activate. Error Code 0xC004E003.

I presume this is something to do with this laptop not just being licensed by the key but also by something in the BIOS? Or a subtly different OEM version of Windows 7 Professional as opposed to the retail version I installed? Am I screwed or is there any way I can license this?

2 Answers 2


Okay, so you bought the Dell with the Windows 7 OEM already pre-installed - the key they (Dell) use during manufacturing is likely NOT the same as the key behind the battery.

If you had installed from Windows 7 Dell OEM media, then it likely would NOT have prompted you for a key due to what it sees in the BIOS with that media to activate itself.

You reinstalled Windows 7 with retail ISO/media onto the Dell machine rather than Dell OEM media so it probably needed that key behind the battery to check in and confirm it's (the retail you used to install) authenticated.

I'm surprised the retail did NOT come with it's own key to use for this, and I'm also surprised the OEM key behind the battery allowed activation against the retail ISO media -- you may have just gotten lucky with the build and revision of the media but I've personally had trouble with this before so I always use manufacturer OEM media with Dells and HPs (at least with Windows 7).

  • The retail did come with its own key - it's what I used to install my own personal Windows 7, for which I am obviously using that key. As for getting lucky, I'm glad I did. I don't still have the OEM media (it probably comes bundled with a load of Dell crapware anyway!)
    – Jez
    Commented Oct 25, 2015 at 9:25

I took the battery out and looked behind it and noticed a sticker that had a completely different product key on it. I tried that one and activation was successful. I have no idea where NirSoft ProduKey was getting the old product key from or why it was wrong!

  • 1
    That's because the program detected the opk, not your OEM key Commented Oct 24, 2015 at 21:13
  • 1
    For those wondering, "OPK" means "OEM Preinstallation Kit" (I hadn't heard of it) and I still don't quite understand why that ends up having a different key to the one that is presumably hardcoded into the BIOS. Why doesn't Windows detect said key and update the Windows 7 key to that in the registry? Then you'd know the proper key.
    – Jez
    Commented Oct 25, 2015 at 9:48
  • It does, starting with certain Windows 8 pc's. It's a EUFI feature Commented Oct 25, 2015 at 12:45
  • @Jez - Windows 7 machines don't have a code loaded into firmware. That only happen with the change to Windows 8 machines. Canadian Luke is mistaken that its a feature of UEFI though. Windows 7 machines supported UEFI long before the change to COAs with the release of Windows 8.
    – Ramhound
    Commented Oct 27, 2015 at 13:08

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .