Install trouble - BIOS ?

[John French]

I have an old Pentium II (266 MHz) which runs Windows 2000 OK (slowly!), 
so I thought I could use it as a mail server. However when I boot up 
with the Ubuntu CD, I get :

[4294667.296000] ACPI : Unable to locate RSDP

We then go to the install screen, and

Loading essential drivers...            ok
Mounting root file system...

It hangs there for a long time, and then goes to a black screen with

[198.393748] hdc : drive not ready for command

I suspected it might be a BIOS problem, but I am unable to find an 
update for this old box. Any bright ideas for a workaround ?

John French