I have the client downloaded onto one of my computers but i'm attempting to put it on a different one for means of having more than one person at my home able to play pso at a time. Thing is the other computer has an anti virus software that is deleting the psobb.exe file every time i download it. I'm not exactly sure how to stop the software from seeing the .exe as a threat. any suggestions?

You will have to go on the anti virus/firewall and alow the program
depends what anti virus u have..nd how to do it. so you'll have to look up how to put threats on the alow list