Could not load file or assembly ''Interop.Excel, Version=1.5.0.0, Culture= neutral, PublicKey

Could not load file or assembly 'Interop.Excel, Version=1.5.0.0, Culture= neutral, PublicKey Token=null' or one of dependancies. The system cannot find the file specified.

In my app the excel was openning perfectly even after the setup.
I am basically openning a existing file in my Resources.
But i Changed the file name in the Resources then its showing this error.

Is this due to the change in the file name ?
Or any other reason behind it.

Plese guide me

[478 byte] By [TapasChoudhury] at [2008-1-9]