FileDrag

FileDrag is a lightweight and portable application which displays information on file types. It can be seamlessly handled, even by users with no experience in software programs.
Since this is a portable tool, FileDrag does not come with an installation package. In order words, you can even store the app on a USB flash drive or other removable device, save it to any computer and directly run its executable file.
What's more important is that the Windows Registry does not receive new entries, and no leftover files can be found on the hard driver after program removal. Plus, you can carry FileDrag in your pocket whenever you're on the move.
The interface of the tool is based on a plain window with a simple layout. So, you can use the 'drag and drop' method to load an item into the working environment; FileDrag automatically displays a description on the respective extension.
In addition, you can use the undo, cut, copy, paste, delete and select-all functions by opening the right-click menu, as well as make FileDrag stay on top of other windows. The tool does not put a strain on the computer's resources, since it requires a very low amount of CPU and system memory.
We have not come across any issues throughout our testing; FileDrag did not freeze, crash or pop up error notifications. On the downside, the app's features are pretty limited. An interesting aspect is that it recognizes all executable files as "Settlers IV Saved Game" items. Other than that, FileDrag offers a pretty straightforward solution to finding out information on file extensions. Unfortunately, it has not been updated for a very long time.