The old fan is probably an old AMD / Intel socket 478 fan. The new one is probably a socket 775 fan. They use entirely different mounting bracket methods. So no, it likely will not work at all if the fans look significantly different. I could tell you for sure if you take pictures of both fans and post them here.
Your best bet will be to take off the failed one, take it down to a computer store and tell them to sell you a new one.
Assuming its a socket 775 fan, there will be 4 black screw thingies that look like they will take a slothead screwdriver bit. Turn them in one direction and they release. Basically there is a small white plastic split barrel below that black turn screw, and to install the fan you place that barrel into the socket hole and then push the black plastic screw thingy down until it spreads the barrel and locks the fan in place. There is also the issue of the thermal paste you need to put in between the cpu and the cpu fan heat sync. That has to be just thick enough to provide good thermal contact, but not thick enough to act as an insulator, frying your CPU. You also have to make sure you get the CPU heat sync down in one try. if you lift it you can get air bubbles which will also do bad things to your cpu.
Installing a CPU fan isn't too terribly difficult once you have done a few of them, but its one of those areas where things can go catestrophically wrong if you don't know what you are doing. I strongly reccommend finding someone local there that can show you how to install the first one properly so you don't melt your cpu.
Here's a video that shows the process for a socket 775 CPU. the process is the same for Core i7 or higher CPU's as well. http://www.youtube.com/watch?v=orp58URhQtg