Uhm... if I were you i'd loose bootmagic and just use good old LILO. First make a dos boot disk!
Just incase this screws stuff up! Try something like
from the DOS command prompt to remove boot magic and make sure you have a clean MBR. Then boot using your Linux boot disks (hopefully you made these during the install!), edit /etc/lilo.conf so that the boot line reads
(assuming you have IDE harddisks, not SCSI [you're probably on IDE]). Now assuming that your FAT/FAT32 partition that holds your Windows install is /dev/hda1 also add the following lines to /etc/lilo.conf
other = /dev/hda1
label = windows
table = /dev/hda
Now save and close the file, then run
from the command prompt (the Linux one that is) to reinstall LILO. Now reboot. Hopefully you will have LILO
appear on your screen at boot time. If you hit the CTRL key then you'll be able to type 'windows' to start Windows or 'Linux' to start linux. The later assumes that the linux install setup the 'linux' image, if this doesn't work then at the LILO: prompt hit TAB and it will show you the available images, one should clearly be a linux image.
Post any questions back here. I've done the above from memory so it doesn't specify a default image, a timeout and assumes that the linux image is there already. If you get the above to work then post a message back here and I'll reboot and look for the other options for you... I'm in Winblows at the moment...
HTH and Hope That Makes Sense Too (HTMST??!? Might have to start using that)