So I went ahead and upgraded to slackware 12. After I upgraded I went ahead and downloaded and installed the following: kernel-generic-2.6.21.5-i486-2, kernel-modules-2.6.21.5-i486-2 and kernel-headers-2.6.21.5-i386-2. I than went ahead and remove the rest of the other kernels after modifying lilo.conf. So everything is workong OK at the moment but I went looking for the kernel-2.6.21.5 source and couldn't find it!!! Where is this file? I haven't been able to find it. Am I supposed to use a different kernel source file? Any help would be greatly appreciated.

You just need to install the kernel source package. It's

kernel-source-2.6.21.5_smp-noarch-2

according to my package log.

Is this kernel source the same for kernel-generic? I'm asking you this because there is the smp in the name... Thanks for the info.

There's only one kernel-source package provided on the Slackware 12 disks. And it's the smp one. You should also run kernel-generic-smp, even if you have only one processor. There's no performance penalty, but you'll be able to compile your own kernel modules if you need them.

the non smp kernel source is in /extra. Read the readme.txt for install innstructions.