Windows 7 admin profile problem, need help

Hi folks, got a rather complex situation i need input on.

Four year old HP laptop, came with Windows vista installed, i upgraded to Windows 7 ultimate in january with the university discount, I do believe it was just an upgrade CD, 32bit. I've been pretty much the only user so made an admin user profile for myself and a guest profile just in case which isn't admin. A month or two ago i could no longer load my admin profile and am stuck with the guest one that has no admin powers - i can't install or change anything in the system. Tried everything, can't do recovery or create new admin profile or fix the original one. So the only option i see is reinstalling windows. So here's where i'm at: I can't find either of the vista or the windows 7 upgrade CD's or the keys that they came with. I'm planning on building a new gaming rig soon - waiting to take advantage of some black friday/cyber monday deals - and will thus be buying a new copy of Windows 7, 64-bit for this one. Now the questions:

- Most ppl get OEM virsion from newegg or w/e when they build; i read that non-OEM versions come with two discs, one for the 32-bit version and the other one for the 64-bit, but only one key, is this correct?
- When i right click on My Computer and go to properties I see a Product ID, is this the Windows 7 key that i can use for reinstalling or a completely different number altogether?
- if that is a legit key, would it be for the Windows 7 ultimate upgrade or Windows vista?

So as you can tell I was hoping that I would be able to just get one box of Windows 7 home premium, non-OEM version, instal 64-bit on new rig with the fresh key and use the 32-bit CD for the reinstall on the laptop using the old one that is hopefully still good.

Would appreciate any help/input, thanks.