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Problems using a Modem or Serial Card in Windows 2000 / XP

This is a problem with the modem or serial card itself, it is requesting IO resources that are not available behind a PCI-PCI bridge.  The device properties report that the modem is not working because of an error "code 10" or error "code 12".
Modem PC-Cards are usually assigned resources based on standard COM ports (IO address 0x3f8, 0x2f8, 0x3e8 or 0x2e8). These addresses are usually not available on the PCI bus on some motherboards.

Modem or serial cards that request 'any' IO address do not suffer from this problem.

We have observed this problem on a Dell Dimension 4100S motherboard with i815e chipset but it may also occur on other motherboards.

Get-around for "Standard PCMCIA Card Modem":

Download the mdmgen.inf file and install it in the following way:

Alternatively :

Manually assign the resources using "basic configuration option 0004" (on my modem this is any IO, any IRQ; you may have to experiment with other configuration options that will allow you to change settings). Then assign a fixed IO address in the same range of IO addresses claimed by the second PCI bus (This range is above 0xD000 on my Intel D815EEA motherboard), and any available IRQ. (I used 0xDFF0 and IRQ 10).  The modem then will work. 

More information (including pictures - approx 70KB)

Fix for AT&T KeepInTouch PC-Card Modem:

Download the icmodem.inf file and install it in the following way:

Fix for TDK CyberExpress 5600 PC-Card Modem:

Download the TDKmodem.inf file and install it in the following way:

This fix could also be applied to other modems, but the inf file will require manual editing to match your particular modem.  Refer to your modem manufacturer for further information.