The system forgot the root password
 

One weird problem happened to me. I cannot login as root. I swear that I have not change my root password, but somehow, the machine just don't let me logging in. I don't have the USB bootdisk with me, and I only have the install DVD with me. What can I do? I'm thinking about wiping out the thing and reinstall it (I have /home on a different partition, so I don't worry much about losing the data). But is there anything I can do before coming to such drastic measure.

I'm using Slackware 12.2

yeah that IS drastic, and there's no way it could "forget" a password... on the bootloader prompt, edit the boot command (press "e" on grub, can't remember what it is on lilo if that's what slackware still uses), and just add a "1" to the line then boot. this will boot you to single user mode, automatically logging you in as root, where you can run "passwd" to set the password to whatever you want.

And if that doesn't work, you can use a live or installation CD/DVD, mount the root partition and edit /etc/shadow removing the password field for user "root". You can set it to something non-empty with "passwd" once you boot back to your normal system.

Well, if the root password was really changed then this would suggest that the system was compromised...

What services are you running?