Finally I uninstalled everything from Audio Inputs and Outputs and Sound, Video, and Game Controllers in Device Manager, checking the box to delete the drivers, and scanned for changes.
I tried windows update, that did find newer drivers, but alas no change. I downloaded and installed the newest win8 drivers from ASUS (win 10 STILL not available), this got me a 'microphone' that was 'not plugged in', like a jack mike on a desktop PC. Under sound video and game controllers there was Conexant Smart Audio HD and some Nvidia virtual audio device. Only Speakers (Conexant Smart Audio HD) under audio inputs and outputs.
ASUS UX303L, sold with win8 after win 10 update notice microphone missing from recording devices and device manager.
