Why the fuck is C:\Windows 75GB 
💀
@matrix
Haven't used Windows for extended periods for too long. I know a lot of bloat accumulated in time from updates, but 75GB sounds way too much. Try running Windows' Clean Tool (or whatever it was called).
@matrix
Also, make sure to also use the "Clean up system files" option in Disk Cleanup if you haven't. (can't believe I actually ended up searching that things name)
@matrix
Get WinDirStat to help you see where the bloat is coming from.