Do I assign different or the same class id to 32-bit and 64-bit versions of the same IFilter?

Question

I've implemented my own Microsoft Search IFilter. I need two versions of it - 32-bit and 64-bit for deploying them on corresponding systems.

In case of IFilters for any file extension I can only register one IFilter class id. Which means I can only use one version on any system. So having two class ids seems useless - it only makes the automatic installer more complex.

Do I reuse the same COM class id for both or do I use different class ids?

Answer 1

Always use a different CLSID. Dont reuse COM CLSID. You can make them both use the same IID, but always different CLSID.