A DLL Stands for Dynamic Link Library.DLL is a small file that include library of functions,normally datas can be shared across multiple functions. There are two ways to register DLL in windows.
1. Self registering files.
Almost all dll files are self registering,they includes information required to store themselves in the OS and registry.Self registration files will automatically store informations themselves on your machine and accessible when this is required.
2. Manual Registering Files.
Manual registration is simple.Login your computer as administrator.(Pleasae copy the DLL file in to actual location or the directory where file is located)
Go to Start > Run > type regsvr32 ” Filename.dll” and press Enter. you can see a Confirmation Message.