I have two hard disk drives:

(D0) on which Windows XP Pro and Xandros are both installed and
(D1) on which I DELETED the Suse Linux 9.3 Pro partitions there
using Partition Magic by a "Delete and Secure Erase"

I would like to UNINSTALL Xandros and INSTALL instead Suse Linux
10.0, but Xandros' boot loader is blocking the operation.

Xandros explains how the program can be UNinstalled using the
installation disk, and although it DOES uninstall the distro Xandros' lilo boot loader continues to appear whenever one reboots the system.

I have tried to use Windows XP installation disk to fix the
mbr (master boot record) using the REPAIR option but it does
not restore the system as it was before when Windows XP Pro
was the only operating system on the computer.

What I would like to do is:

1. UNinstall entirely Xandros from the HD (D0) and
2. INSTALL instead Suse Linux 10.0

so that on that disk drive (D0) both Windows XP Pro and Suse
Linux 10.0 will be there.

Later on, I would also like to perform a new INSTALL of Xandros on
the other disk drive (D1) to continue examining and working with
it.

When you install SuSE, you can have it overwrite the boot loader that Xandros left behind. No need to get rid of it separately.

When I change the BIOS settings to:

1st Boot Device Toshiba CD DVD ROM
2nd Boot Device Toshiba CD DVD ROM
3rd Boot Device Toshiba CD DVD ROM

with the SuSE Linux 10.0 CD DVD disk inserted in the CD DVD drive, and reboot the system the installation is bypassed for some unknown
reason.

It's not LILO that's blocking you. I don't know what the problem actually is, but at least I can tell you to look elsewhere than at LILO.

Whey I try to install SuSE Linux 10.0 using the CD DVD ROM drive
on the screen appears on the black screen:

GRUB Loading state1.5.

GRUB Loading, please wait...
Error 22

That's all.