Thanks for your replies,but I'm just as confused now.Bobkn your answer seems to suggest that I can't change from 32 to 64 bit no matter what,yet other posts suggest you can with a clean install. If I install my old hard drive(with 32 W7 on)in the new system and then do a clean install is that O.K? Or can I fit a new hard drive in my new rig,install 64 bit before connecting to the internet,then wipe my old drive.How can MS know that I've got it installed on 2 hard drives if they're not connected to the internet at the same time?Maybe I'm not making myself clear - I only want to connect one computer to the internet at a time,but want to make sure the new system works properly before ditching the old.
You can switch to X64. It would be legitimate, as long as you stay within the 1 license per machine requirement.
As far as I know, the only check on whether a key is in use is when you initially activate a Windows installation. If the key is in use, you have to activate by phone. You are supposed to remove Windows from an old system before activating it on a new system, but there is no explicit de-activation. I'm less sure about the WGA (Windows Genuine Advantage) scheme, but I think that's mainly to detect hacked versions, or inappropriately installed keyless corporate versions.
If you're a sufficiently skilled , um, storyteller (liar), you could probably persuade Microsoft that you have Windows installed on only one machine, and they'd give you the new activation code. Not the sort of thing I'd care to try.
If you want to temporarily run two copies of Windows, the suggestion to run the second without activation may be your best one. You can re-arm the 30 day grace period as many as 3 times, allowing you up to 120 days of use without activation. I doubt that's how Microsoft intends Win7 to be used, but it won't get you flagged as violating the license agreement.
As far as I know, there are no online checks for multiple machines activated with the same key. I have known people who activated XP on two or more machines with the same key. They had no trouble doing that because the activation server reset after 120 days. (If the two activations were further apart than that in time, the second machine could be activated automatically online.) It's not clear that the people I knew who did this realized that they were violating the EULA. They blissfully continued to use the two machines, online at the same time.
