Can a beats studio3 wireless over-ear defiant headset be used with a non-apple computer?

If that computer supports the same Bluetooth, and is able to pair with the headphones through the Bluetooth settings, they should be able to work together.

Bluetooth is odd though, some computers may try to connect multiple bluetooth devices, like a phone, mouse, keyboard, and headphone and get overwhelmed. So if you are using a lot of wireless devices, test just the headphones alone, while using wired devices initially for everything else.