Classical Opus is freeware and it is not to be sold for profit. It is available only for Windows95/98/Me/NT4.0/2000/XP/Vista/Win 7 and above.

Classical Opus's latest version can be downloaded either from this home site or from Tucows site. No other site is authorized to maintain the latest Classical Opus version.

Windows 64-bit UPDATE (Windows 7, Vista, XP 64-bit only) 
If you are installing Classical Opus 4.0.0 on a Win 64-bit system such as Windows 7 64-bit please download and install this update after you install "Classical400.exe" below.

.File    : CLOPUS_500x64_Update.zip (2012 update)
          Please click on the link above to download file)
Size    : 1.5MB 
Content : Classical Opus 64-bit update (installation of Classical400.exe below is required before you apply
          this update). 

Guide   : The CLOPUS_500x64_Update.zip update will update the sorting engine to Classical Opus 5.0.0.
          1. Download and Install Classical400.exe below
          2. Download and unzip CLOPUS_500x64_Update.zip above
          3. From the resulting CLOPUS_500x64 folder, copy all files to the "C:\Program Files\Opus400"
             directory where you installed Classical Opus 4.0.0
          4. By copying please allow for the replacement of any files within "C:\Program Files\Opus400" folder
          5. From now on run the "Classical500x64.exe" or "Classical500x64" file and everything will work
             fine. You will be using Classical Opus 5.0.0 on your 64-bit system.

Windows 7, Vista, XP, and below

After you download the compressed file below, click on it to run and follow instructions on the screen for the uncompression and the installation of the program

File : Classical400.exe (2007 edition)
 (Please click on the link above to download file.)
Size : 2.2MB
Content : Classical Opus 4.0.0 (2007 edition) program, help file, manual, tutorial, music glossary.