I still cannot start this 486 after formatting the drive. I think the 'Oracle' Peter Cooke is correct in sugesting that it is trying to boot off the hard drive and not the floppy, due to the boot sequence set to c:, not a:.
The problem is, I cannot get to the CMOS or BIOS to make changes because I dont get a prompt to hit DEL while booting.
This is the sequence on restart,

486DX2 BIOS v1.2R1.5
016000KB Memory Good
384 Shadow Cashe Ram
256 Cashe Ram

(reads A drive, then)

1 diskette drive(s)
1 fixed disk(s)
1 parrallel port(s)
3 serial port(s)

8087 (SX) Coprocessor Installed
Memory Cashe on
RAM BIOS enable

Invalid system disk
replace the disk , and then press any key.

It does this regardless of a disk in a:.
the question is, how do I stop this procedure to make changes?
F5, F8, DEL, all have no affect on stopping the boot. Is there some other key combernation to stop this? It is very frustrating!
The startup disk is virus free. (I have another computer next to the roblem one that I am on now, 233PII)
Grateful for any help