Windows 10. Retail vs. OEM. Home vs. Pro

[Enigma]

Planning to rebuild my computer and I've been pricing out each part for the upgraded computer but I've hit a snag regarding Windows 10. First things first, my current computer is running Windows 10 Pro 64bit. Got it free like the majority of Win10 users. Since I am reusing my hard drives, can I still run the computer without reinstalling Win10 or would I need to purchase a copy?

If I do need to purchase a copy, is there a difference between retail and OEM? Is there much of a difference between home and Pro versions? I'm using Pro now, would I notice any difference if I went with Home?

[Vendetta]

OEM licenses are locked to the hardware they came on. In the case of Windows 8 and 10 the license key is flashed into the DMI and that's what activates the license instead of the online activation.

All the Windows 10 discs (or more likely download licenses or USB sticks) you buy are the same license now, no seperate retail and system builder licenses.

If you're not on a windows server network, you won't notice the difference between home and pro (except for the extra fifty quid missing from your bank account). Pro is basically about having domain join (and bitlocker).

[Executor32]

Windows 10 has no issues moving over to a completely different set of hardware, but obviously it becomes deactivated. If you like, you can give it a shot, and when you're at the desktop open the Settings app and go to Update and Security -> Activation and enter your Windows 7 product key when prompted. It should still activate, despite the supposed deadline in July.

If you're signed in with a Microsoft account and are on the Anniversary Update, your digital license will actually be tied to your Microsoft account and not just that particular set of hardware, so it might even activate automatically for you in that case. You can check this right now if you go to Settings -> Update and Security -> Activation; if it says "Windows is activated with a digital license linked to your Microsoft account", then you can probably move the drive to the new hardware without having to reactivate.

Otherwise, you can just create a Windows 10 Pro install DVD or USB stick using the Media Creation Tool, and when installing enter your Windows 7 Pro key. I'm 100% certain that works because I still do it all the time at work.

[Enigma]

If you're signed in with a Microsoft account and are on the Anniversary Update, your digital license will actually be tied to your Microsoft account and not just that particular set of hardware, so it might even activate automatically for you in that case. You can check this right now if you go to Settings -> Update and Security -> Activation; if it says "Windows is activated with a digital license linked to your Microsoft account", then you can probably move the drive to the new hardware without having to reactivate.

Mine is linked.

So once I update, I can give this a try, if not I can always grab a Win 10 Home.

[Executor32]

Not even. Since it's linked, at best you won't have to do anything at all, and at worst you'll have to go into the Settings app and reactivate it.

[Tribble]

Windows 10 Pro also has the "defer upgrades" option, which basically takes you out of the guinea pig testing. Windows 10 updates have been known to wreck havoc on home users from time to time so it might be worth considering if you absolutely need to mitigate the risk of a bad update.

[Vendetta]

Windows updates only tend to be a problem for people who don't restart their PC regularly.

And haven't turned fast startup off.