Where is the auto-installed ActiveX control located on my computer?
You can list and manage your auto-installed ActiveX controls by going to Internet Options -> [“Browsing history” or “Temporary Internet Files”] Settings -> View Objects. If you have a new enough version of IE, you can also use its “Tools” -> “Manage Add-ons” -> “Enable or Disable Add-ons” feature. Typically, Internet Explorer stores things like this in the “Downloaded Program Files” subfolder of your WINDOWS or WINNT folder. You can also try searching your hard disk for a file named alttiff.ocx, but be warned that Microsoft’s file search utility may skip files in your “Downloaded Program Files” folder, so you still have to look there manually. If AlternaTIFF is working, you can find out exactly where it is by using it to view an image, right-clicking on the image, selecting “About” from the menu, and looking at the line that begins with “Location:”.
