Cannot Configure Network with More than One Network Card

When you remove or disable a Plug and Play (PNP) network card and add a legacy (ISA) network card, the PNP network adapter is redetected the next time you restart the computer, or it may continue to run in real mode.

Legacy network card support is an all-or-nothing proposition. All cards in the system initialize in real mode if the NDIS2 network drivers are loaded. If you remove the card using the Network applet in Control Panel, but leave the card on the computer, Windows 95 automatically detects and configures the card again the next time you start the computer. If you disabled the card using Device Manager, the card still runs in real mode because its configuration is contained in the Protocol.ini with the other cards that are installed.

You can edit the Protocol.ini to remove information and bindings to the Plug and Play card, and you can disable the card using Device Manager. However, this is a temporary resolution; any time the network configuration is updated (automatically or by using one of the Control Panel applets), Protocol.ini is rewritten.

This problem usually occurs on computers that have networking chipsets built into the motherboard. In other cases, you can physically remove the Plug and Play network card from the computer to solve the problem. If you can run the legacy card in protected mode only, then you can disable the Plug and Play card and the system will function correctly.