Can't Enable Hyper-V on Windows 10 Enterprise

I have a machine running Windows 10 Enterprise.  It used to have Hyper-V enabled, but I disabled it to run VirtualBox.  I've now removed virtualbox.  Every attempt I've made to enable Hyper-V results in error 0x80073701 (assembly not found).  I've tried every suggestion I could find to get it working with no luck.  Here is my systeminfo:

Host Name:                 -------

OS Name:                   Microsoft Windows 10 Enterprise

OS Version:                10.0.16299 N/A Build 16299

OS Manufacturer:           Microsoft Corporation

OS Configuration:          Member Workstation

OS Build Type:             Multiprocessor Free

Registered Owner:          -------

Registered Organization:   -------

Product ID:                00329-00000-00003-AA641

Original Install Date:     8/12/2018, 9:19:09 PM

System Boot Time:          7/1/2019, 5:46:13 PM

System Manufacturer:       HP

System Model:              HP ZBook 15 G4

System Type:               x64-based PC

Processor(s):              1 Processor(s) Installed.

                           01: Intel64 Family 6 Model 158 Stepping 9 GenuineIntel ~2904 Mhz

BIOS Version:              HP P70 Ver. 01.17, 1/29/2018

Windows Directory:         C:\WINDOWS

System Directory:          C:\WINDOWS\system32

Boot Device:               \Device\HarddiskVolume1

System Locale:             en-us;English (United States)

Input Locale:              en-us;English (United States)

Time Zone:                 (UTC-08:00) Pacific Time (US & Canada)

Total Physical Memory:     16,303 MB

Available Physical Memory: 11,311 MB

Virtual Memory: Max Size:  21,167 MB

Virtual Memory: Available: 15,544 MB

Virtual Memory: In Use:    5,623 MB

Page File Location(s):     C:\pagefile.sys

Domain:                    -------

Logon Server:              \WPSCSASADDS1

Hotfix(s):                 19 Hotfix(s) Installed.

Network Card(s):           5 NIC(s) Installed.

                           01: Cisco AnyConnect Secure Mobility Client Virtual Miniport Adapter for Windows x64

                                 Connection Name: Ethernet 2

                                 Status:          Hardware not present

                           02: Intel(R) Ethernet Connection (2) I219-LM

                                 Connection Name: Ethernet

                                 Status:          Media disconnected

                           03: Intel(R) Dual Band Wireless-AC 8265

                                 Connection Name: Wi-Fi

                                 DHCP Enabled:    Yes

                                 DHCP Server:     192.168.1.254

                                 IP address(es)

                           04: Bluetooth Device (Personal Area Network)

                                 Connection Name: Bluetooth Network Connection

                                 Status:          Media disconnected

                           05: Microsoft KM-TEST Loopback Adapter

                                 Connection Name: Npcap Loopback Adapter

                                 DHCP Enabled:    Yes

                                 DHCP Server:     255.255.255.255

                                 IP address(es)

Hyper-V Requirements:      A hypervisor has been detected. Features required for Hyper-V will not be displayed.

I've been able to successfully install the Hyper-V manager, but not the platform. 

I've tried everything I could here.

I tried running the wu10.diagcab tool with no luck.

The system seems to think that virtualization software is already running, but it isn't.  Is this contained in a registry key somewhere?