Get the Ableton Live Suite for Windows for free. It includes all the instruments, sounds, effects, and cutting-edge features you could possibly need to create music. With Live's Session View, you can either improvise without being constrained by a timeline or create a conventional linear arrangement. You can freely switch between musical parts and experiment with ideas without having the music stop you from moving further.
The greatest digital audio editing program available for Windows is Adobe Audition Pre-Activated offline installer, which can be downloaded for free via torrent or direct download. Use it to mix, create, and design sound effects.