Did you install (not "download") the Dell chipset drivers?  That shoud be done before installing any device drivers.

PCI simple communications controller is your dial up modem

To Reinstall:
Locate your DELL modem cd
Verify that your modem is attached to a working phoneline
Insert the cd (select english)
Select utilities
Select modem drivers
Select your OS (WinXP i guess?)
Click next
Click finish
Go back to utilities
Select Install modem helper
Click next
Click next again
Click yes to restart the computer
Click finish
Remove the disc
After restart double click on the modem helper icon
(The Modem Helper initializes and indicates that Modem Helper Needs to Reinstall Your Modem).
Click yes
Follow the prompts
Click finish
Close modem helper