What is the ruling on working to install computer programs and train employees on them for a client who sells alcoholic beverages among other products in a duty-free market, and what should I do if my company pressures me to do so?

There is no harm in installing a program free of any mention of alcohol or any function related to it, and training on it in stores that sell permissible items. However, if the program is related to alcohol or the store sells prohibited items, then it is not permissible to install it or train on it.