Fan malfunctioning

[Aetre]

I'm having a bit of computer trouble that seems to be stumping just about everybody I bring the question to (including Gateway tech support), so I thought I'd get your input on the subject. I hope you don't mind.

Anyway, here's the problem:

My Gateway laptop is always overheating because the cooling fan by the cpu is acting very strange. When the comp starts up, the fan goes on for five seconds, then turns off. It stays off until the cpu gets so hot that some of the laptop keys on the keyboard literally start melting. Then the fan will turn on for five seconds, turn off for five minutes, on for five seconds, off for five minutes, repeat. Eventually the interval between the five-second spurts will decrease, but by then, the keyboard's so hot I can't touch it without burning my fingers.

Every tech support person I've spoken with (five in total) has told me this: as long as the fan turns on at all, it's probably not broken, but the settings on it are messed up. Supposedly, laptop fans may be set only to turn on once the cpu reaches a certain temperature. This saves energy for the battery, but it can result in overheating, since as long as the temperature (as detected by the fan) is hovering right around the threshold for fan operation, the fan will turn on and off in spurts. The solution, then, or so I'm told, is to change the fan settings so that it's always on, not just on sometimes.

They tell me this is supposed to be located in something called "BIOS," which on my computer means I have to hit F2 when the system starts up, then search for the fan settings and change them. Well, I've searched all over BIOS, and there's nothing at all there that resembles "fan settings." There's "peripherals," but that just contains settings for the USB ports on the computer. Then there's "power" settings, but that just contains the battery options (standby after 5 mins., etc.). Nothing I've found changes the fan operation.

Is there another folder I should be looking for? Is the fan itself in fact broken and in need of replacement? Or is there a way to open the computer and alter the fan manually to get it to switch on whenever the comp's on?

If it helps, I'm running Windows 2000 Professional, the CPU is a Pentium III, and the fan's driver is simply labelled "ACPI Fan." The only modification the Control Panel will let me make to the fan is to remove or "troubleshoot" this driver, but of course, when I press "troubleshoot," it says the device is working properly.

Edit: Extra info:
The Computer is a Gateway laptop, model #450SX4
Memory: 30GB Hard Drive, 1/3 full; 256MB RAM