When use regsvr32 /u "C:\Windows\System32\Macromed\Flash\Flash10a.o cx", it
says "DllUnregisterServer in Flash10a.ocx succeeded.", but the addon still
isn't uninstalled from IE7, which can be judged from the "Manager Add-Ons"
page - the Flash10a.ocx is still there.
Similar issue exists when use regsvr32 to register an ActiveX dll,
successfully registered but the DLL doesn't appear in the "Manager Add-Ons"
page, any ideas?

Edit: The OS Platform is Windows Server 2008 Enterprise, IE ESC is turned
off and security levels for all zones are set to default. The ActiveX can be
installed successfully if let IE7 download and install it.