I need to activate Windows 7 ultimate x64 on my workingstation and I have to buy a product key. I'm considering opting for a solution with a greater value for money: purchasing a cheap used laptop with Windows already preinstalled, uninstalling it and recycling the product key for activating Windows in the workingstation I am currently using. (I would install a distro Linux opensource on the new laptop instead).
I have several doubts:
1) Product keys used for x86 operative systems do work for the x64 of the same version as well (for example, do they work both for Win 7 ultimate x86 and Win 7 ultimate x64) ?
2) the laptop I would buy comes with Windows preinstalled: after having uninstalled it, is there the risk to face any additional troubles while using its product key for activating Windows on a second device?
3) If any troubles by attempting doing that, could I still apply for Microsoft technical support?
4) I saw that product keys come with different names (OEM and so on): should I keep those differences in mind for my purpose?
OPTIONAL - - -
I'm also considering purchasing a laptop with Windows PROFESSIONAL installed instead than ULTIMATE: in that case I should downgrade my windows 7 ultimate to the professioanl edition in order to use the product key of the former -> is there any remarkable implication I should considere before doing that? (I mean data loss, the necessity of reinstalling softwares, any kind of incompatibility with the product key, etc...)