I'm not sure what you mean by searching to download it; it's just a replacement access point / new term for the Layout Manager, which used to have an entry point in Dreamweaver under many of our extensions (i.e. Insert > CSS Menu Writer > Layout Manager).
I've now resolved this by un-installing, clearing the winfilecache file and then re-installing again. I'm not sure whether this was what did the trick, but the Preset Manager is now working correctly. Thank you.