What is the ruling on selling computers with commercial accounting software to a beauty salon primarily frequented by women who display their adornments, and is this considered assisting in something unlawful?

It is not permissible to sell to shops whose غالب (majority) of customers are immodestly dressed women (mutabarrijat), because this is considered cooperation in sin and aggression, which is forbidden by His (Allah's) saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." And whoever gives up something for the sake of Allah, Allah will compensate him with something better.