Some files act as "activators" or "loaders." They claim to install Windows from scratch but actually install a heavily modified version of Windows filled with bloatware, browser hijackers, and spyware that is difficult to remove.
Instead of a repack, it is safer to use official Microsoft tools and legal activation methods: windows 8 highly compressed repack
If you need a lightweight, fast, Windows-compatible environment, you have better—and legal—options. Some files act as "activators" or "loaders