Installing a wireless network card in a computer with an existing dial-up modem typically does not cause issues, as both can function simultaneously. However, for successful internet connectivity through the wireless card, the computer must be properly configured. Key considerations include ensuring that the dial-up modem is connected to the internet first, enabling Internet Connection Sharing (ICS) if sharing the dial-up connection, and verifying that the wireless card drivers are installed and configured correctly. Users have reported that both types of connections can work together without problems, provided the settings are appropriately managed. If the wireless card recognizes the signal but fails to connect to the internet, troubleshooting steps include checking network settings and ensuring compatibility with the wireless router. Additionally, using both connections may slow down internet speeds, particularly if the dial-up modem is still active. For optimal performance, it is advisable to disable the dial-up connection when using a broadband wireless network.