Need help with start up problem ASAP!!

[Brilopad1]

I'm having a really weird start up problem with my iMac G5 that i need to get fixed ASAP because i just put it up on ebay. When the screen turns grey during start up, a small white box with a picture of the earth on it appears and flashes for about 15 seconds. It then switches to a folder with a picture of the two-face apple thing and a question mark flashing back and forth. It does that for 15 seconds then continues the normal start up. I don't want to take it off of ebay b/c i want to get it sold before the new imac comes out. Here is a link to a video of what my computer is doing.

http://www.youtube.com/watch?v=w1WMbQhxBmE

For some reason my camera wouldn't focus. I have an external hard drive with a backup of my entire computer, but i lost my install disk. Any suggestions?

 

[yellow]

Login. Open System Preferences. Go to Startup Disk. Choose your boot device. Restart. Fixed?

 

[Royale w/cheese]

Make sure your not booting from a network, that probably isn't there.

edit, yeah, your trying to boot from a nonexistant network. I just replicated this problem, and that is the answer. See yellows post for the fix.

 

[Brilopad1]

Yep, that did it. It just randomly started doing that. Thanks a bunch!

 

[yellow]

Probably you help down N at some point during a startup procedure (or your n key sticks) and it was looking to NetBoot.