there can be several reasons for a kernel panic. But you can always boot the system with a resue cd or floppy. Once you have booted, you can try to undo the things you have done to cause the kernel panic.
A kernel panic never just apears. You have to have done somthing to cause this.
The next time you have a kernel panic (lets hope never
) just tells us that you did prior to this panic and the people on this form will do the best they can to help you correct the mistake. Also, it's a good idea to post you exact error message.
If you don't have a rescue disk, it's a good idea to make one. See this site