Invalid ActiveX/COM entries?

In recent days, Norton WinDoctor reports over a hundred 'Invalid ActiveX/COM Entries'. It says "The ActiveX/COM sections of your Windows Registry contain one or more invalid entries. This can cause documents to open improperly, applications not to run, or your computer to crash." They mostly look like this:

Missing or Invalid Key: "DisplayServer.AppSettingsBasic"
Problem ProgID, "DisplayServer.AppSettingsBasic," refers to an invalid ActiveX/COM entry,
"{9B5EC720-9A44-4811-8B9F-24BD53F2050D}."

Missing or Invalid Key: "DisplayServer.AppSettingsBasic.1"
Problem ProgID, "DisplayServer.AppSettingsBasic.1," refers to an invalid ActiveX/COM entry,

Missing or Invalid Key: "Video_TVServer.VideoZoom"
Problem ProgID, "Video_TVServer.VideoZoom," refers to an invalid ActiveX/COM entry,
"{D385E909-3F89-4ECD-B38F-AC11F9FE6F1C}."
etc

But if I select the option to Delete any of these entries, Norton reports 'Repair Failed'.

FWIW, I don't seem to be having particularly unstable performance on this XP Home (SP1) PC, although over the past couple of weeks I have had a couple of crashes in which my monitor just went suddenly blank.

Can anyone help me identify/fix this issue please? Or even guess what these entries are supposed to do, as I'm technically out of my depth here.

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Terry, West Sussex, UK