Searching for installed filters



Hi

I am a newbie in directx programming.
I require to make a program in C# which searches for all installed
directx and 3rd party filters in any machine and can give a list.

I dont know how can I do this.
If I have to search the registry then what exactly I need to search
and how can I ensure that all filters are found and none is left.

any help
thanks in advance
Preeti

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