wifi: no hardware installed after update 10.13.2 on imac

I connected my imac with an ethernet cable and manually downloaded High Sierra again tonight and reinstalled it. Voila! I added wifi under system preferences/network and the wifi indicator worked normally instead of showing no hardware installed. Was the automatic download corrupted last night? Did apple apply a fix? I watched the installation tonight and it was a very smooth process with one restart in contrast with the multiple restarts last night. I have never dealt with a stressful upgrade like that before.

thanks for replying. I tried resetting NVRAM and SMC and restarting holding down the D key. Internet recovery begins but then I receive an apple.com/support -3403D message with an exclamation point in a black triangle. I went and purchased an ethernet cable. The update did not install smoothly. I guess I will try to reinstall the update to fix whatever was installed incorrectly.