Why is Valorant broken on PC? (Vanguard fails to start, blocking the game from launching)
Riot Client opens but Valorant itself won't launch, often with a Vanguard service error. Vanguard runs as a kernel-level driver that starts at boot; if Windows updates or other security software interferes with driver load order, it fails silently. Fix: Restart your PC fully — Vanguard's boot-level driver sometimes needs a clean restart after a Windows update, not just relaunching the game.