Operating System not found error

Hello, I wonder if you could help me

My dell inspiron 1564 running windows 7 that yesterday came up with an operating system not found error.

I have tried all the suggestions found through google searches and forums and nothing has worked. (system repair, restore, diagnostics through dos, etc.)

I have the reinstallation DVD and the other driver and utilities cd, but neither have proven helpful. When I try to reload, the windows seven option isn't available. When I try to reinstall, it says I don't have a hard drive. When I try to reinstall the driver to access the hard drive, it says it is not on the CD.

Does anyone know any options?

I'd appreciate the help

-Scott