Problems to update FFDShow

[NudeFan]

When I try to start some movies, I get the message:

BS.Player cannot play the media file.
You don't have necessary codec installed, file may damaged or not media file.

Click 'Find codec' to try to find codec.

After clicking 'Find codec' the message, that Haali Media splitter had been found. I confirm. that BS.Player shall run the CodecManager to install the filter. Then I get the message, that an old version of the FFDShow is found on my system and it's recommended to uninstall this version.
Then the CodecManager opens and FFDShow is marked for uninstalling. I click on Uninstall selected, get the message Operation 'Operation Complete' and the again ,the message that an old version of the FFDShow had been found on my system. I can do the same steps as described before again and again, but the FFDShow will not uninstalled.

Any idea how to solve this issue?