Product Key Questions?

I have read various things on this forum and other sites about Windows 7 product keys and activation under various circumstances, and I wanted to ask again here just to verify accuracy.

1) Can a Windows 7 Professional x64 Retail Upgrade product key be used to clean install Win7, or are additional hacks/workarounds required? I've read various things here, from clean installs activate fine with no additional workarounds, to Activation fails with a "This is an upgrade key" message," to having to re-install Win7 over your clean install or performing some registry hacks (see here: Paul Thurrott's SuperSite for Windows: Clean Install Windows 7 with Upgrade Media) to allow activation. I've also read that x86 upgrade keys are upgrade only & only allow activation when upgrading, but x64 upgrade keys are full keys & can be used with clean installs. Is this true?

2) Can a Win7 Pro x64 Retail Upgrade product key be used to activate Win7 Pro x86 as well? I've read that keys are edition specific (i.e. Professional) but not architecture specific (x64 vs x86). Is this true as well?

Since I can only activate once without having to call MS, I'd like to know the correct answer to these questions, as many of what I've read contradict each other. Thanks!

I am not going to answer the questions about how to perform a clean install from an upgrade disk, because there is too much confusion, at the present time.

I can give you other advice, however. When asked for the key number, while installing, just ignore. You actually have 30 days before you need to activate.

My advice, install the way you think is best. If it does not work, try another, and then another. Once installed, try it for a week or so. When satisfied, activate. I would also make a copy of your hard drive, so that you can reinstall with the copy in the future and not worry about activation.

My copy of 7 is due to arrive Tuesday, so I will be putting my money where my mouth is.

Good luck

Thanks Rich! Just to clarify, I'm referring to strictly to activation, not installation. I've already successfully clean installed Win 7, I just haven't tried to activate it yet. The hacks I referred to are in reference to getting a successful activation with a upgrade key. I'm just trying to sort through the confusing information I've been reading in an attempt to find an answer to my 2 questions.

You have 30 days, (you can get 2 more 30 day extensions) to validate.
I know what you are referring to and there is no definitive answer at present. There is even some talk that MS, after this rush is over will reset their equipment and invalidate some validations that have been made in error.
I am going to install as soon as I get my copy of 7 then wait a while before I validate; to let the dust settle.