KB11873: How to register and unregister .dll or .ocx (control) files using the RegSvr32 Windows utility

In some instances, after installing a program or patch, some Dynamic Link Libraries or Controls may not be registered automatically; one may therefore have to carry out the procedure manually.
 
NOTE: Registering a file modifies a machine's registry in the background. See the warning message at the bottom of this page.
 
Registering and unregistering .dll or .ocx files is accomplished via the RegSvr32Windows utility. To register a .dll or .ocx file complete the following steps:
 

1. Open a command prompt session by executing "cmd.exe." To do this, click on the Windows Start button, select the Run option, and click Ok. User must run this command using an Administrator account. If the user is not an Administrator, go to Start > All Programs > Accessories > Right-click on Command Prompt > Run As... > Select and Administrator account.
    
2. Use the command prompt to navigate to the directory where the file to be registered/unregistered resides.
    
3. Once there, use the following syntax:
   a. To register a file:
    
   regsvr32
   
4. b. To unregister a file:
   regsvr32 /u
   
5. NOTE: Replace the string with the complete name of the .dll or .ocx control file to be manipulated. For example, if a .dll file by the name of "sampleDLL" is to be registered then the syntax would be as follows:
    
   

C:\> regsvr32 sampleDLL.dll
For more information on the regsvr32 utility please consult the following Microsoft knowledge base article:
 
http://support.microsoft.com/kb/q249873/
WARNING:
Modifying registry values incorrectly may cause serious, system-wide problems that may require the re-installation of Microsoft Windows. Any edit of the registry is done at the user's own risk. Since these are user-initiated changes, they are not covered by any Strategy warranty. If using Microsoft Windows, the user should backup the registry and/ or update an Emergency Repair Disk prior to alterations.