It is very handy to see the preview of most frequently used files like images (.png, jpg etc.), videos (.avi, .mpeg, .mp4 etc), audio (.mp3, etc.) spreadsheets (ms excel, .xls, xlsx etc), text documents (msword, .txt, .doc, .docx) etc. in Windows Explorer itself. No need to open each and every file to see the content.
One simple step to get the preview in Windows Explorer
In your Windows Explorer Go to Organize -> Layout -> select Preview Pane as shown in the following screen shot.
Preview Pane of Windows Explorer is added at the right side of Windows explorer. Audio, Video files can be played from this pane itself, if required Windows Media player also can be opened easily from here.