OS from one PC to another PC to get Windows 10

I have a full version of Windows 7 on one Computer and I need to put it on another Computer so what would be the best way to do this? The reason why is if you have the full version of Windows 7 you can upgrade it to Windows 10 for free.

Are you wanting to move the Windows from one computer to the other, or are you wanting two different installations of Windows at the same time? Two different installations of Windows at the same time requires you to purchase a second license.

The Windows 7 license is not affected by the upgrade to Windows 10. However, there is still only one license for Windows which still limits it to being legally installed on only one device at a time.

If you want to keep all applications and user data from your old PC to the new PC (but not both at the same time), then you can try connecting your hard disk to the new PC and see if it loads Windows 10. In order to succeed The new PC must have similar hardware (from one generation of Intel/AMD to another, the closer the better. Mixing Intel with AMD will most likely result in BSOD). Of course you will have to activate Windows again and by doing that you will bind the license to the new PC and cannot use it on the old PC anymore. Assuming you manage to load Windows 10 on the new PC and activate it, you then need to update all drivers to match the hardware of the new PC. This is a bit tricky as any incompatibility masked by a generic driver might cause a BSOD when using the official (Intel or whatever) driver. To play safe I recommend to clone your current disk on a new disk and connect that to the new PC. If Windows load successfully, update all drivers. If after restart everything is OK, activate Windows and keep the new disk. I would keep the first disk as a backup.

I think it is perfectly clear that you cannot legally use the same license of Windows at two different computers. It doesn't matter if you upgrade one of them to Windows 10. So I hope the OP wants to transfer his current Windows installation to a new PC to avoid reinstalling everything from scratch and that he will then discard of the old PC. This is legal, for details of how to do it see my earlier reply. If you do what I suggest and you get BSOD because of some incompatibility, all you can do is install Windows 10 without format and then copy all your data from Windows.old folder Of course you will need to reinstall all your programs though.