dual boot

My machine has windows 2000 pro, recently I used partition magic to create a new partition on my hard drive. Somehow this wiped out my windows installation and the computer would not boot up. I reloaded win 2000 from a norton ghost image I had done before creating the partition. Now when it boots up it shows I have a dual boot with 2 win 2000 partitions, both with “default” on them. If you don’t choose the right one the computer simply locks up and does nothing. How do I delete the bad operating system? I have checked to see if there are more than one partitions but there’s only the one I’m using.

Thanks,
Mickey