Invalid System Disk on Compaq Presario 5250?

[Westcoast]

This system error "Invaild System Disk - Please insert disk and hit any key" occurs on start up with out any disk in the floppy. When using a boot disk I get a "VFAT error" With this Presario model I can get into computer setup by selecting the F10 key but it has no access to the CMOS settings at all. I have no clue as to how to get to the CMOS settings on this computer! Can anyone help me?
I've looked at the Presario site and downloaded a couple of exe's but these can't run in DOS mode....grrrh!
Please don't tell me that I have to get a new hard disk

 

[vbMax]

With some of their PCs, Compaq stores the CMOS
settings on a special partition of the hard drive
not on a chip on the mother board as most other
(normal) manufacturers do. If you replace the
original hard drive, the CMOS settings are no
longer available with the F10 key. You can,
however, use a special system disk which was
provided with the PC when it was new. If you
boot from this special disk, you can then change
your CMOS settings. If you do not have this
"special" disk, you can download in from Compaq's
web site. I had to do this last year - it was a
painful experience. Good luck!