Complex sentence: A runtime version for viewing videos only was also made available as a free add-on to Windows 3.1 and Windows 3.11; it then became an integral component of Windows 95 and later.
Split into simpler sentences: A runtime version for viewing videos only was also made available. Originally released as a free add-on to Windows 3.1 and Windows 3.11, it then became an integral component of Windows 95 and later.