1. Click the Windows 'Start' button on the computer that contains the DLL file. Type 'cmd' in the search text box and press 'Enter.' The MS-DOS window opens.
2. Type 'REGSVR32 /s DLL_name' where 'DLL_name' is the name of the .NET DLL file. The 's' switch silently installs the file without any output.
3. Press 'Enter' to install the file. Registering a file only takes a few seconds. After you receive a 'Success' message, you can use the DLL files in your programs.