I know there are tools which can detect nude content and then block them. But they are all available in browser or for a web-site. Is there any software which can scan all directories and provide a list of such media content present on the computer (Windows 8.1)
Any software that tries to do this via image recognition will normally either be looking for a preponderance of skin tones, which a) suffers from the variance in skin colours and b) will tend to match head shots as having too much skin, or on looking for certain shapes - both methods either produce way too many false positives or false negatives sometimes both.
You might be better with a search and categorising program that saves the tags and you can tell it to show you all the untagged photos for tagging/deletion/etc. Darktable, is one of many applications that will let you do such things.