You don't need to re-install any CD. Your system, for what ever reason, is missing the AUTOEXEC.NT file. It happened to me before. All you need to do it got to c:\windows\system32\ on another machine and copy the file to a floppy. Then copy it to the system32 folder on your pc. If you want I'll e-mail the file to you. I would fix it though because sooner or later you'll have this problem again.
You can try installing the new printer. If it works your good to go. But sooner or later you should fix the problem.