In contrast to the executables. dll files may not work independently and therefore do not have their own installers. Usually dynamic libraries are installed automatically with the installation of the program, for whose service they were intended. If you received such a file separate from the executable, the first thing you need to figure out the location in the computer root folder of the application, which should run this library. If we are talking about some kind of system the program should look in the system directory - usually it is one of the subdirectories of the Windows folder on the system drive. With applications, things are even simpler - just right click the label on the desktop or in the main OS menu, select "Properties" and click "file Location". As a result, the "Explorer" window opens the working directory of the application in which you need to find a subdirectory with the dll files.Often these libraries are part of automated systems of stock trading - trading robots (expert advisors), indicators, scripts. Such systems are often distributed without automatic installer and pack multiple files from the downloaded archive have. In the root folder of each type of the trading terminal for dll files has a separate folder. For example, in the popular terminal MataQuotes for them given a directory inside the libraries folder experts.Once the correct location of the library file was found, you can proceed to installation. This procedure is simple move the dll file to the correct folder in the file Manager, copy (Ctrl + C) or cut (Ctrl + X) this object from the places of temporary storage, navigate to the working folder and paste (Ctrl + V) the contents of the clipboard. Keep in mind that if you are trying to replace an existing dll file with the new file, the OS may refuse to do so, issuing an error message. This will be the case if the model file at this point blocked using his program. The problem is solved simply - close the app and try again.