I have inadvertently taken the run level out of the inittab file and rebooted.I now cannot get into my Mandrake Linux system to change it. It defaults to run level 9 and says there are no more processes in this run level. How can I change the run level during boot time?

Hmm, I didn't know there was a runlevel 9...

Type "single" at the boot prompt to enter single-user mode. From there you should be able to mount /etc and edit /etc/inittab. Re-enter the line id:x:initdefault:, where x is your desired runlevel.

hmmm... i'm guessing that perhaps you don't have a boot prompt. if so, i've got some bad news adam. what you've got is referred to as the runaway level 9 problem. if you have a rescue disk, now is the time to use it, or if your installation cd has an option to get to the prompt, those are your only hopes. i had this problem a while back, and not a single guru i asked had anything useful to add. you need to edit your /etc/inittab file, but i'm guessing that you already know that. the trick is to get to the file.
in my unfortunate case, i had to do a clean re-install, which wasn't that bad, because i had just done a back-up. the only other real options are to try to install a small linux on another partition and then use that to fix the old system, but i've never tried that personally. if you find another way around, let me know.

Doh! Of course- no runlevel, no prompt. Need boot disk. Guess I hadn't have enough cofee when I posted that response