Disclaimer: Modified Windows ISOs are not supported by Microsoft and may contain altered system files. Always test such operating systems in a virtual machine (like VMware or VirtualBox) before installing on bare metal.
Windows 8.1 Super Nano Lite is a highly specialized tool. It is an impressive engineering feat for squeezing life out of ancient hardware, but it should be used on a primary computer, for online banking, or for handling personal data. If you choose to experiment with it, restrict its use to an offline hobby PC or an isolated virtual machine.
For better security and performance on older hardware, experts at PCMag suggest: