If you'd like a lightweight Linux distribution for that aging hardware, but you want a more modern-looking UI, consider Waydog.

Abstract: With increasing penetration of inverter-connected power sources, such as renewable energy sources (RESs), the equivalent inertia in the grid decreases. Employing maximum power point tracking ...

Yes, Virt-Manager does have a slightly steeper learning curve than VirtualBox. (I'll write an article soon on how to create a VM with Virt-Manager.) However, the reward for getting up to speed is a ...