Windows Vista X64 RC1 Product Key

[Stel]

I had taken part it Windows Vista Customer Preview Program and had bought Windows Vista Beta 2 DVD box having both versions of Vista (X86 and X64). I did not had any issue in installing them on my system's but today i downloaded both versions of Windows Vista RC1. Installation of X86 went fine using the same product key that i had used for installing Vista Beta but i am not able to use it for X64, what might be wrong? any idea?

[Viceman]

I wanted to know if you have tried installing RC1 Ultimate without entering key? If not than you can try that out first and apply the key after installing it successfully. In order to apply key after installation go to Start > Right click on Computer > Properties > under Windows Activation just click ton the link saying "Change Product Key" and enter it.

[Stel]

I haven't tried installing RC1 Ultimate without Product Key but i will try out the trick you have mentioned and will post back the result.