Disclaimer: Newbie

I was dual booting a system with Win2k/Redhat 9 with the Redhat
install on a secondary drive. When I wanted to switch, I just changed
which ide channel was primary in the BIOS. I decided to keep the
system Redhat, and move the other drive to another system. Now I get:

mount:error 19 mounting ext3
pivotroot: pivot_root(/sysroot,/sysroot/initrd) failed:2
freeing unused kernal memory: 368k freed
Kernel panic: No init found. Try passing init= option to kernel.

when trying to boot. I'm sure it's because I removed the other drive,
and now the boot drive is hda instead of hdb.

How do I fix this?