Re: compaq presario 56K-DFi modem Problem
First uninstall the device by right clicking the device in Device Manager, then choose "uninstall"
Shut down the pc and remove the device.
Now boot back up again and then shut down again.
Re-install the modem but this time put it in a different pci slot than it was in originally.
Re-install the drivers and you should be good to go.