I have recently installed Snow Leopard on my aluminum Macbook . I dont have a lot of GB available, so I decided to reinstall Leopard and then install Snow Leopard again for more GB. I accidentally inserted the iMac install disk 1 (Not the Macbook install disk), because I have a iMac as a home computer. When I inserted the install disk, it tells me to restart my computer. I click Restart. But, after trying to boot, it comes up with the white screen. This lasts for about 15 seconds. After 15 seconds, my Macbook restarts again! It keeps repeating to restart over and over again. After about 15 restarts, I tried and ejected the disk and restarted my Macbook without the disk and see if it cancels the installation. When I boot it up with no disk, it cant read my HD anymore! It comes up with that flashing folder with a question mark on it. Any ideas?? I tried to insert the disk and the same restart problem occurred. I found my original Macbook install disk and tried inserting it into my macbook at startup and see what happened. It still shows the ? Folder. I tried a lot of things like booting with the CD at startup (Command-C), still no luck. I tried holding option at startup as well. It shows a big lock icon where I insert the administrator password. I inserted the password, and nothing happened. I kept trying over an over again. HELP!!! UPDATE: PROBLEM SOLVED!!!!!