Both on the hardware and software side.
Don't neglect how convenient a user interface can be.
Miss Windows XP or 7? Then I have a free, open-source alternative for you ...
The Windows Subsystem for Linux (WSL) is a set of software tools that basically lets you install and run native Linux applications on a Windows PC without rebooting ...
If Windows is your preferred operating system, consider these open-source apps. There are numerous open-source apps available for almost any task. These are all free to install and use on Windows.