I just installed Win XP on the first (primary) partition, which was
working fine. Then I set up Linux (Debian) on the second partition using
a boot floppy, which was still ok.
Then I decided to use grub as boot loader. Since I haven't had any
experience with it, I must have done something wrong here:
I used 'grub-install /dev/hda' to write grub into the MBR and set up the
operating systems in /boot/grub/menu.lst as follows:
kernel /vmlinuz root=/dev/hda2
Now I can boot to Linux, but ...