Unable to see Video Thumbnails

Hello everyone
while clearing my last doubt about codecs of video for pond5 , I am facing problem in seeing the thumbnails of the video rendered.. i rendered in Avid DNxHD and also ProRes codecs but rendered video doesn't show up. Initially i was unable to play the video itself in window media player then i chose VLC player to play it.. but the thumnail never came up ..neither in WMP nor in VLC while my other videos and images do show their thumbnails... i have been searching the solution in google, youtube and forums for any old relevant thread but no use. All giving information for not showing thumbnails at all...to go to file explorer and in folder view tab to click the view thumbnail option but my case is different..
Something like http://flickr.com/photos/190764397@N04/50556088037/in/dateposted-public/ Finally i had to post here to ask.. if someone knows the solution.. kindly help
*Sorry cant make out how to post link here

https://www.videohelp.com/software/Icaros

Thank you CHDM... i just made it by downloading additional codecs.. though WMP is still not running but every player is showing thumbnails now.. uhhh.. finally.
I think Icaros also does the same task.. provides missing codec..