WAIT, NO! You can still save it.
You will need to use the slack rescue CD though. anyway . . .
1. Put the CD in the drive and set the BIOS to boot CD first.
2. Do this:
mkdir /mnt/hd
mount /dev/*your hd* /mnt/hd
chroot /mnt/hd
vi /etc/shadow
*remove the encrypted password for root*
reboot
*remove cd*
3. When you get the login you should be able to get in with no password, just hit enter or return when it asks.
-Hope this helps.