Cannot delete Mods

Hello, I was curious if anyone else was having the same problem as me with modding. I installed some mods, they worked great, but now I have decided that I want to try new ones. Well, I decided the easiest way was to delete the whole game and download a fresh installation to mod. The only problem is, when I install the fresh installation from Steam, the mods do not go away. I have tried deleting them from the steam App, my computer, everything, but the saved games and mods just re-download when I download it from steam. Any suggestions on how I can fix this?

Thanks,
Torm04