Platform notes: Windows
Pegasus is available for Windows 7 or later, and should work out of the box.
Pegasus uses Windows' built-in video playback support (DirectShow). This supports many video formats without problems, bux in some cases it might be necessary to install separate codecs, or a codec pack (a common case for example is Steam videos). The K-Lite Basic pack is a popular choice that should work well for most cases, you can download it here.