The OSIRIS Level 1 Services is a software library that provides access to the OSIRIS Level 1 radiance data products.  The Level 1 data products are stored on disk on an orbit by orbit basis and all the information is spread over several different files.

You can download the Level 1 services software for Windows from here

Windows x64, Osiris Level 1 Services Version 2.48

Windows x86, Osiris Level 1 Services Version 2.40 

The OSIRIS Level 1 Services documentation is also available for download.