Executing docker version returns the following results.
C:\\Projects> docker version
Client:
Version: 1.13.0-dev
API version: 1.25
G
For me the error was resolved by stopping a virtual Ubuntu instance that'd been running in Hyper-V:
The system cannot find the file specified. In the default daemon configuration on Windows, the docker client must be run elevated to connect. This error may also indicate that the docker daemon is not running.
Once Ubuntu instance had been stopped, and Docker Desktop had been restarted, my usual docker commands ran just fine.
PS: I had the idea to try this because of an Error Log that Docker Desktop had helpfully compiled and offered to send to Docker Hub as user feedback... the log appeared to indicate that my machine was short on RAM, and Docker was failing for this very simple reason. Killing the Ubuntu instance solved that.