No Fixed Disk Present

I have a Compaq Deskpro 486 machine, which all of a sudden displayed a ‘system disk error’ and since then will not boot. I am trying to reinstall windows, using 95 boot disk – and ran fdisk and got the message NO FIXED DISK PRESENT.
I have looked inside and checked cables etc and looks ok. Also I should mention that it is making a few strange noised, one being a clicking sound (every now and then) the other, I can only describe as a bleep (similar to that of the old Atari tennis machines) if that makes sense?
Any suggestions/ideas would be greatly appreciated, it is my son’s machine and I would like to sort it out for him if possible.
Thanks
Mal