iPhone 3G possible dock connector problem?

Well I just bought a refurbished iPhone 3g, it was unlocked at the time, but I wanted to use it solely for it's iPod capabilities, rather than it's phone aspects. I ran into a small problem, that being that the phone is not recognized by my computer. The phone recognizes that it is plugged into my computer, and will charge, but my computer will not recognize my phone, thus, will not allow my phone to sync with iTunes. In addition to that, I decided to take an "proactive" attempt at fixing the iPhone myself, and did an "Settings and Data" reset. Excited, and hoping to see some sort of result, I come to you all disappointed to say that my iPhone is bricked. It will turn on (after pressing the power button, or plugging it into a computer) and will show the apple sign. It will then have the loading circle that will spin for a bit, then freeze. It will stay froze for a while, then reset itself, and repeat the process. Now I've heard that I am able to reset my iPhone, by putting it into "DFU" mode, but I'm not sure this will work, seeing as how my computer still fails to recognize my iPhone. If it's of any importance (which I'm sure it is), I have a Toshiba Satellite L305 S5968 Laptop Running Windows 7 Ultimate. If there is any possible solution to my scenario BESIDES buying a new iPhone, PLEASE tell me what it is...

-Thanks

Is it possible to return the phone or exchange it for another? (You said you bought it refurbished.)

As to putting into DFU mode, right now that's your only choice - if it'll work.
You might also want to see if another computer will recognize the phone. Either another PC or Mac. Mac preferably since it will already have iTunes where most PCs do not.