After update to 17.5.2303 Wifi Drivers Cannot Be Loaded - Code 31

[REDACTED]

I updated to Avast 17.5.2303 build 17.5.3585. 203 (virus definitions 140813-0), after a restart, and a smart scan, Windows 8.1 cannot load the wifi drivers and gives code 31. Specifically: This device is not working properly because Windows cannot load the drivers required for this device. (Code 31) {Operation Failed} The requested operation was unsuccessful.

The device is USB-IF xHCI USB host controller, drivers are xhcipport.sys and wdfcoinstaller01009.dll located in windows\system32\drivers. I tried updating the drivers however windows reports the drivers are up to date. Then I did a manual restart, and still no wifi.

How do I get wifi working again?

[bob3160]

2 places to check for help:
https://h30434.www3.hp.com/t5/Notebook-Operating-System-and-Recovery/USB-IF-xHCI-USB-Host-Controller-Code-31-Device-manager/td-p/5022890
http://en.community.dell.com/support-forums/laptop/f/3518/t/19493150