Tell us the exact make/model of the router as well as the make/model of the wireless machines and what version and patch level of Windows they use.
Generally, it will involve accessing the router's web based setup and configuring encryption keys in the wireless section. Then you'll have to connect and supply the same wireless keys for each wireless workstation.
Generally, it will involve accessing the router's web based setup and configuring encryption keys in the wireless section. Then you'll have to connect and supply the same wireless keys for each wireless workstation.