Sharp PC-W100T Operation Manual page 80

Installing the PCMCIA Card Driver
When you insert a PCMCIA card into the notebook, the driver for the card will
usually be installed automatically. If automatic installation is not possible, a dialog
box will appear so that you can follow its instructions to complete the installation.
Some PCMCIA cards use the COM3 or COM4 port which may conflict
with the COM1 or COM2 port already used by other devices in the
notebook. If your PCMCIA card uses COM3, set the COM1 Port: option
in the Setup Utility to Disabled. If the card uses COM4, set the COM2
Port: option or IR Type: to Disabled.
Hardware Expansion 6-3
6