0xC004E003
That's the error message I get when I try to activate Windows Vista on my media center. The product key is good; I called Microsoft and they even generated and gave me a different product key to try. Same message.
Vista has decided that my grace period is over (60 days after installation) and it's time to shut me down. I tried to activate online, using the automated phone system, and with the help of a human representative. No luck - I get this error message, which they don't have an explanation for. The folks on the phone can't help me.
The knowledge base mentions this error code here, but the steps don't actually help in my case.
Isn't this the nightmare scenario that people predicted when WPA was first introduced? Well, it's real, and I'm living it.