How to register an ActiveX control (.ocx) manually

You can use the Microsoft Register Server (Regsvr32.exe) to register a 32- bit .ocx file manually on a 32-bit operating system

Regsvr32 [/u] [/s] 

Note
  /u means Unregister the .ocx file.
  /s means Silent Mode (display no messages).

Ref http://support.microsoft.com/kb/146219