Win 7 32 bit and 64 bit

I have not been able to find an unequivocal answer to this question: I bought a box containing 32 and 64 bit Windows 7. I installed the 32 bit version. I'm now thinking of moving to 64 bit. Can I install the 64 bit version on the same computer with the same product key?
To an earlier thread asking more or less the same question, one poster replied yes, if the 64 bit version was acquired legally, but a further poster went on to say only one install per product key. I am at a loss to reconcile these two statements, so I will ask again: Can I install the 64 bit version on the same computer as the 32 bit version is installed with the same product key, either side by side (in a dual boot configuration) or as a replacement?

Hi wapanap - Welcome to w7forums

Simple terms: You can only have one install of windows per key. Yes you can install either 32-bit or 64-bit with the same key but only one install at a time. If you decide to change bit versions you will need to delete the old install or get a second key.

Thanks for your quick reply. How do Microsoft know whether I have deleted the old install? And is there way of getting a trial period of the 64 bit version to determine whether it is fit for my purposes?

Installing without adding a key (if you have this option) will give you a grace period (I forget the amount of time).

And how do Microsoft know I have deleted the old install?

I don't know the answer to that question. I couldn't even give a guess as to how they manage keys. There has to be a small level of trust in the customer the way things are done.

Microsoft will know that the old install is gone. Don't worry about it, just install the 64-bit version and you'll be fine.

Remember you can only have one install of the Windows 7 operating system per product key. Running 32-bit and 64-bit on the same computer will not work on the same product key.

You have a 30-day grace period on the new install.

Once you decide to keep it then just go ahead and activate it and it'll all be good.