Windows DUN/RAS Error 602 "The port is already open."
Reboot.
Make sure that no other programs are using your modem. Fax software, Supervoice, etc...
Ctrl-Alt-Delete, if you see RNAAPP loaded, then go to the RNAAPP fix page.
AOL can also cause this issue. If AOL was or is installed try deleting the AOL Adapters in the Network Control Panel then reboot and reinstall the Dialup Adapter.
Is the modem using an initialization string? If so, try removing it and replacing with: ATZ
Does the user have Quicken 2000? If so, try disabling the Quicken Download Manager, found on this page.
A Dell article on this issue can be found here.
Try uninstalling and reinstalling the modem.
Try checking for spyware/adware/virii that may be trying to utilize the modem.
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