Even if you use version info, you'll see this happening in some cases. Usually it goes away if you unregister the OCX (in C:\WINDOWS\OCCACHE\ or C:\WINNT\OCCACHE) using REGSVR32.EXE. The recommended way of doing this is: Exit Internet Explorer. Run "regsvr32.exe /u c:\windows\occache\MyActiveX.ocx" Restart Internet Explorer and hit the web page again. If you deploy extra files that you ActiveX is using you might be helped by knowing that all the stuff is being pulled down to your OCCACHE directory and if Internet Explorer determines that there is a conflict - it'll put some files in OCCACHE\CONFLICT.x (x is a number) directories.