Move Startup Disk to Hard Drive

Hey,,

sorry if this has been posted before but i'm having a noob problem. My Macbook recently stop working on me, and won't boot up. I decided to start fresh so I reached for my hard drive with a recent Time Machine backup. I told Disk Utility to erase the current drive and replace it with the Time Machine back up. Now, when I boot back into Leopard, my hard drive shows up as my start-up disk. I can't boot or do anything without being tied by USB to that (huge) drive. Did I do something wrong? I want my start up disk to live inside my computer.

Holding Option on startup will allow you to choose your boot drive. To set the default, hold Control and press the arrow under the drive you want as the default (it should turn into a circular arrow).