[Ell201275]

I've just been given a small form factor mini-desktop that has an Intel Core i5 6th gen, 16GB RAM, Intel HD Graphics, SSD etc..

I'd like it to replace an existing old CuBox with Kodi which boots from a memory card.

I'm not sure how to boot Kodi straight from a USB stick (The SSD is faulty) ?
What version of Kodi do I need? Portable? Windows? 

This machine is not going to be used for anything else apart from Kodi.

Thanks in advance. 

[Jogee]

Kodi is just the application and doesn't include an operating system.  You might want to look at LibreELEC.