Here's the story: I was changing cdrom permissions from root to user 'cos my cdrom didn't want to execute my audio cd's with something like "You need more permissions" or something in that style about permissions, and I thought (don't know what went into me) I should change hdc (my hard drive) permissions from root to user and, when I restarted my computer, none of kernels (2.4.26 and 2.6.8.1) would boot with error messages such as "--- System halted" (for kernel 2.6.8.1) and "Couldn't mount root fs" (for kernel 2.4.26). Is there any way to fix this except reinstall?

The next time, instead of change ownership for device file, try to add your user to the corresponding group of that device file in /etc/group

How did you change permissions ? And what are the new permissions ?

You could boot with install slackware CD 1 or 2 and then mount the root partition and re-change permissions, but I would think you did more than just change permissions (the boot fails)...

I changed them through properties>permissions window I set adan as user instead of root, then rebooted and then it gave me the errors.

For my part, I never use any window to set system permissions, I use command-line only, and I never had problem with command-line tools to change permissions.

The problem is I don't know how to use chmod man chmod doesn't make it any better...