You could use the ethernet port on Comcast's EMTA (Embedded Multimedia Terminal Adapter) but check to see if that incurs any fees.
The di-524 was an ok router but if it can't do WPA (I can't remember) this it has to go.
I need to consider a new cable modem. I checked the Comcast website and it indicates that my current modem, D-Link DCM202 is at the end of its useful life and/or no longer supported. I'm looking for recommendations on a new modem for a not very techy person to install. Should I also replace the D-Link router, DI-524, at the same time? My current setup is an HP m7750n desktop w/Windows 7, 2 ghz + 4 gb ram connected directly to the router. We also have an Ooma voip phone.