This document details four different ways to register a DLL. Each method yields the same result, so use the one that is easiest for you.
Double click on the DLL. An Open With box appears.Click the Other button, and then browse out to Windows\\System or Windows\\System32 directory.Click on the REGSVR32.exe file, click Open, and then click OK.
On the taskbar, click on the Startbutton and then click Run.In the Open textbox, type regsvr32 "javascript:void(null);" (quotes should be included around the path and filename).Click OK.
Open a DOS prompt.Change to the directory where the DLL resides, then type: regsvr32 DLLname.dll.
In Windows Explorer, drag the icon for the DLL file and drop it on top of the regsvr32.exe file (located in Windows\\System or Windows\\System32 directory).