Any chance there is a non-bootable formatted hard drive connected?
It may be trying to "see" the system files there.
You should get a different error if no drives are connected.
                         Rick
From: "Doug & Sharon White" <[log in to unmask]>
>         I have a strange problem.  I have an old 486-100.  I was changing out the
> hard drives in it and when I went to reboot I got this error message:
>
>         "Invalid system disk. Remove disk and press any key to continue."
>
>         The only problem is.......there isn't any disk in the floppy drive.

                         PCBUILD's List Owner's:
                      Bob Wright<[log in to unmask]>
                       Drew Dunn<[log in to unmask]>