Maybe you don't have proper access rights to the 'Program Files' directory? What's Windows version? What account you're using to create installation?

>Using the installshield express version 3.03 and adding the ms vfp7 runtime libraries merge module fails with this error:
>
>** Error -1023: File E:\rombert\MySetups\firme_aiesec\Express\Interm\MergeModules\VFP.Runtime.0C4A7BA_5A73_11D3_A520_00A0C9231BA1\Program Files\Common Files\Microsoft Shared\VFP\VFP7RENU.dll not found. Unable to copy file {same path} in _VPF_RUNTIME_RES_CORE____X86.3643236F_FC70_11D3_A536_0090278A1BB8 to release location.
>
>Another similar error is given by vfp7t.dll