setting up a wireless network

We have a D-Link DI-514, and I cannot get it to share our cable internet connection, thru Comcast, or to share files with other computers. Every time I go thru the wireless setup process for the router, it does not accept the changes I make and always resets to defaults after it says that it has saved the changes, but like I said, they stay at defaults.
I cannot figure out what I am doing wrong, help please!

I was going to suggest that you upgrade the firmware, but it looks like all of the A,B and C version of your routers only have one firmware version.

You might have to bite the bullet and call Tech Support. But do yourself a favor and call them BEFORE 5 PM Pacific time. After that the calls get routed to India.