I would not recommend using a product key generator to generate keys, you can find em on the internet relatively easy. And as for Windows XP keys, a certain GitHub page has them.
@K3Nv3, There's the Windows Genuine Advantage that got implemented in SP3 if I remember which checked the license of your Windows installation to see if the key was either pirated or whether it's been activated.
Always expect risks on outdated versions of Windows, there's probably a dozen or more vulnerabilities for XP that haven't been patched after the EternalBlue exploit that got leaked from the NSA.
I get the retro vibe of it but he's using a vm worst case just right click delete kind of crazy not to be using up to date software if your system can handle it
I'm running it on a VM, but it's more up-to-date with the latest security patches. There's not a single Wi-Fi adapter connected to this VM. And just to make sure nothing bad happens, I make daily snapshots.
I mean you have to really not know what you're doing to go for a hardcore virus on your main rig these days most just install games directly from steam