My BHO is packaged to a cab file along with accompanying .inf, as most of the ActiveX installers do. On the web page which installs my BHO, I'm using the object tag to have the BHO downloaded and extracted: <object classid="clsid:6E1CBEC2-762E-4840-964B-1F2F36D107F1" codebase="XXXXXXXXXXXX.cab#version=1,0,0,3" name="XXXXXXXXXXXX_object" height=0 width=0></object> I have a major problem with updating an existing version though. Obviously the BHO dll file is in use, and the installation silently succeeds (but the dll isn't updated properly). During the installation I do register an uninstaller so that the users can manually remove an old version of the BHO, but it's the customer requirement to allow updating it without requiring to uninstall an old version. According to this article http://support.microsoft.com/default.aspx?scid=%2Fservicedesks%2Fwebcasts%2Fen%2Fwc042500%2Fwct042500.asp it should be possible to update the files in use after browser restart (when installing an ActiveX) but this is definitely not an option for me. I also know that it's possible to download & run a regular .exe installer packaged to a .cab file, but the customer dislikes this idea as it should take more steps for the user to install the component. Do you think it's possible to update a BHO installed from IE without using external installer? Any help would be very appreciated.