First thing you need to do is open the case and try to figure out which fan is making the noise. It could be either the CPU fan or (one of) the case fan(s). You can just stick your finger into the case fan(s) to stop them for a bit (it won't hurt unless for some reason yours is metal), and see if that stops the noise.
DO NOT do the same thing to the CPU fan, because that could damage the CPU. If it's not the case fan(s), then it's probably the CPU fan, and you'll need to buy a replacement. If you have any kind of warranty on your system, this would be a good time to use it.
I have two questions here.
1.the last couple days when I turn my computer on it is making a very bad noise. It sounds to me like something has a bad bearing or something. The computer boots up fine and the noise gradually goes away after a minute or two. I have never had a problem with the hard drive on a computer before.I am just wondering with this vague description if somebody would have an idea what might be going wrong. I am hoping it is just the cooling fan going bad. But like I say I've never had a hard drive go bad so maybe it is that. Any opinions would be greatly appreciated.
2.I think I know the answer to this, but since I am writing I might as well ask to make sure. A friend of mine just gave me an external Iomega zip drive. It is one that uses a parallel cable. On the back there are two parallel connectors. One labeled zip and the other labeled computer. When I am hooking it up I assume I should run the parallel cable from the computer to the zip connector right. I assume the connector labeled computer is for me to hook a printer or something to.