Desktop making a rapid beeping sound on startup

[charlesr]

My grandad's old Dell Dimension is making a beeping noise at startup so rapid that over the phone it's almost a single note.

It boots fine.

Before I head down there, what things might it be?
Key stuck down? (no sign of this once booted)
New battery needed?

[briareos_kerensky]

Dell guide on beeps does not mention a single tone, maybe the lights in front of the computer will be more helpful.

[originalbadboy]

At a guess I would say keyboard

[importaku]

Unplug keyboard before you boot & see if the beeping continues. I have only ever seen behaviour like that when i have had a key pressed down.

[charlesr]

Cheers chaps.