{Request} Bootable Device - for Dummies

Here is my situation.

I started up my computer, and for reasons unknown my computer said, "Bootable Deivce not found -- Insert boot disk and press any key"

I have searched for resolutions, but I'm not good with too many technical terms, so I'm looking at resolutions I know nothing about.

My Computer:
Sony Vaio - Model: PCV-C41L
Windows XP: Media Certer Edition 2005
Has a dvd burner drive and a hard drive.

If someone could link me a page with the correct solution to my problem that would be wonderful, or if someone could point me in the right direction, that'd be great too.

Thanks for the help.

Tram,

The suggestions found on the below link should help resolve or identify the cause of this issue.

http://www.computerhope.com/issues/ch000229.htm