How can I make my laptop use a phone as a wi-fi adapter?

I have an HP Pavilion dv6400 series laptop with an NVidea chipset which is the subject of a class action lawsuit. The symptom (PDF) that I'm experiencing is that the system fails to recognize that there is a wireless adapter installed. It doesn't appear in Device Manager. In this question, I ask if there's a way to work around this problem.

As an alternative, I'd like to see if there's a way to use an old Windows Mobile 5 phone that does not have cellular service (voice or data) as a Wi-Fi adapter. How can this be accomplished?

The system is running Windows Vista Home and has the latest BIOS (F42) and Windows updates and drivers.

There is no way to "tether" to that older phone. Your best bet is a usb wifi dongle - you can find them for < $10.