My Random Thoughts

The first operating system that I used when I started studying computer science was MS-DOS. It is the previous CLI (command-line interface) of Microsoft's operating system. That's the reason why I am kind of familiar with how the computer handle files through the black and white shell like this. Usually we need to open the file via an executable program (with a file extension of .EXE) to open another file for reading and printing. That's the only way that the file can be recognized by the system. Now, with he GUI of Windows, file handling is different. File extensions are stored in a tree database of the OS specifically via the registry. This were all registered by the application assocatiated to the file.

For example, file extension PPS is associated with MS Powerpoint while the file extension TORRENT is associated with torrent programs such as UTorrent and Bittorrent. These files can be opened easily when double-clicked and immediately open the associated program. However there are files that are registered to the registry but not used for opening files. File extension DLL is a fine example of this kind of file, since it is used as a library of the operating system.

That's why sometimes when the registry was damaged by viruses or malwares, an abnormal event happens to your system, sometimes hangs or stops from working.