Laptop fan continues to...
 

...rotate even when it is not being used. This cannot be normal. It didn't use to do this before. There must be a problem, or is it me?

Any ideas? The noise is becoming unbearable.

I have a Compaq 2700

These fans are usually controlled by a heat sensor on a critical component (the CPU). If the laptop is in an unusually warm place such that the CPU is hot even though no heavy computing is going on (there is always some housekeeping activity) the fan may well run continuosly. OTOH the heat sensor or its circuit may have failed and the particular failure or a failsafe condition may be responsible for the continuous running. Try shutting it down completely and leaving it off long enough for it to completely cool and let it do so in a cool room or even outdoors. Upon restart the fan should only run very briefly at first and then stay off until it is warmed up. If this isn't what happens it would probably be best to take it to the shop for a check.

Thanks but I think I'll have it checked out. There's plenty of space around it and the room is cool so there is an internal problem.

If it didn't do this before then you probably have some software
running that eats more CPU cycles. An easy way to test this would
be to start the computer and hit the PAUSE button while BEFORE
the operating system starts (when the BIOS is listing devices and
such). See what happens to the fan if you let it stay there for a while.

Usually fans are always running, but you might not hear them in
lower speeds. Ofcourse this also depends on the processor you
have in the system.

Funny you might say that.

The funniest thing as happened. Strange is more like. I was checking to see if my anti virus program was activated. Of course not. That's strange. So I avtivated and did an upgrade of my anti-virus program...and guess what? No more annoying fan noise. It is like the problem never existed.

Now, I would like to know how can an antivirus program have any effect on the fan?

But the question is, which program was the culprit if t was another program? It must have something to do with the Anti-virus program or something. Aaah well, it's working the way it's suppose to.

Just wanted to mention that sometimes dust inside the fan can
make you hear it more as well...

Anti-Virus can definitely do this! Usually these programs are very
resource intensive and can eat memory and CPU cycles like crazy.

So I'm not at all suprised that perhaps the AV software was
pushing the CPU just over the edge where it needed extra
cooling and so forth. An update might have made the program
a bit more resource sensitive (or perhaps it was a [slight] bug
they fixed).

Glad you got it solved!