Second windows 10 will take up even less resources than Windows 8.1 -> less space on the hard drive and a little bit less of the RAM.

Is Windows 10 better than Windows 8?

As it has quickly become the new Windows standard, like XP before it, Windows 10 gets better and better with each major update. At its core, Windows 10 combines the best features of Windows 7 and 8 while ditching some controversial features, like the full-screen Start menu.

Which Windows uses less resources?

Of the Windows operating systems, Windows 7 has been praised as being the most compatible with low-resource computers.

• Windows 7 Ultimate runs on a virtual machine with 512 MB of RAM, without any noticeable slow-downs.
• Shows a significant reduction in RAM use over Vista, but was still higher than Windows XP.