cannot boot laptop after kernel upgrade

[Pollywog <croak@shadypond.com>]

I installed kernel 2.4.0 on my ThinkPad 560 and after I was done, I
made sure /etc/lilo.conf was correct and ran lilo, and I rebooted.
This is what I got:

request_module[block-major-3] root fs not mounted

VFS: cannot open root device "301" or 03:01

Please append a correct "root= " boot option

Kernel Apnic: VFS: Unable to mount root fs on 03:01



I then rebooted to the old kernel, 2.2.16 successfully and tried
installing the new kernel image again,
but when I rebooted, I could no longer boot either kernel.

I smell a reinstall; not even my boot disk could start Linux.
Is there a way out of a reinstall?

thanks

--
Andrew