Hi, I am Dave, I will help you with this.
Most likely that game is not on your PC and not using any space on your drive, it is probably just some registry entries left over from that game.
Open the old Control Panel (not the Settings app).
Set View at the top and select 'Large Icons'.
Open Programs and Features.
Can you find Valorant in the list of installed software there?
If you can find it there, choose to uninstall it, then when you get that error, you should be given the option to remove it from the list, select that.