it isn't bootable - i think because it wouldn't fit on one cdrom otherwise; but if yer still interested.... you still have the file, right?
do this as root:
and cd to "/mnt/cdrom/isolinux", read the README.TXT file. It explains how to make a bootable install cd. You'll have to leave off gnome, kde, or kdei or it won't fit on one cd. As for why V. didn't make a 2 cd download with the first being bootable, who knows? or even a small shell script would have been helpful.
remember that slackware will have you do most things yourself, so brush up on the HOWTO's and README's.
or if you'd rather, stick with one that has an easier setup.
-t.