Problems during PBE Client Installation

During PBE Client installation the pop-up window (showed in the figure) tells me "a process" is already running, I have already rebooted my laptop to make sure nothing from Riot was being run in the background and nothing changed, i'm trying to install it on an internal SSD although it results in the same error on the external drive, I was interested in beta-testing Aphelios but am unable due to this Help, plz (~~also, bring League to Linux please, Windows is bad~~) Edit: Mistype Edit 2: Continued testing, the same error occurs when opening the normal Client, but clicking on exiting and attempting to reopen works (does not work on PBE installer)