To run virtual device for emulation of wearable app need to install Intel x86 emulator Accelerator. I read that the recommended method is to use the SDK. Ran the SDK manager from Android Studio, found the option under SDK Tools and installed it – but virtual devices still do not start, saying the accelerator is not installed.
The missing step seems to be that I then had to find the SDK directory (mine was c:\Users\username\AppDate\Local\Android\sdk, which was only visible after changing the setting to show hidden files at the username level) then go to Extras, Intel, Hardware_Accelerated_Execution_Manager and run intelhaxm-android.exe. Once that completed and Android Studio was restarted then the virtual devices would start.