Windows 10: Windows 10 is not updating Windows Defender

Me and my roommate. both bought the exact same HP Envy 360 from Costco at the same time. I installed mine using the Microsoft 'remote' method. He installed his using the 'local only' method. We both have McAfee Antivirus on our machines. When I check updates I continue to have Windows Defender updates frequently updating on my computer. It seems to work with McAfee. I can scan the computer using Defender. On his computer, however, it does not give him the option to scan using Windows Defender and it never calls for an update of Windows Defender. It seems that Windows Defender is somehow disabled on his machine. He is such a newbie that he does not even know or understand what the problem might be. One fellow I asked suggested that Windows is allowing McAfee to manage virus protection: but mine has always continued to update Windows Defender AND update and use McAfee. Why doesn't his computer allow Windows Defender to scan or update?? The only difference I am aware of is the way we installed our initial profile. What is going on?

:)

 

Windows 10 Anniversary Update Issues

Problems with W10 Anniv auto update:

Mom's: (x58 Xeon 5677) Windows Defender was not turned back on automatically (it was "on" in the 1511 edition) and she had a Trojan. Full system scan to eradicate.
Her Epson printer was knocked off, had to uninstall by Device Manager pull USB cable and reconnect cable. W10 did the rest.

Step-mom's: (HP pre built) Windows Defender not turned back on by default. Her USB Seagate Expansion Drive 2Tb was offline so all backup routines were halted. Had to rerun backup plan. Had her do a full virus scan.

Step-dad's: (Dell Optiplex tweaked upgrades) Windows Defender not turned back on by default. Full Scan.

 

Windows 10 Tweaks

Pressing “Windows+Pause Break” (it’s up there next to scroll lock) opens the “System” Window.

Windows 10: In the new version of Windows, Explorer has a section called Quick Access. This includes your frequent folders and recent files. Explorer defaults to opening this page when you open a new window. If you’d rather open the usual This PC, with links to your drives and library folders, follow these steps:

• Open a new Explorer window.
• Click View in the ribbon.
• Click Options.
• Under General, next to “Open File Explorer to:” choose “This PC.”
• Click OK

credit to Lifehacker.

 

SEtting up automatic updates for windows defender on windows 8

I have found this on the internet en have set up a task for automatic definitions update for Windows Defender but a window pops up when this starts to run.
Is there a way to set this without any window popping up so that it just runs in the background?

Now I'm using
"C:\Program Files\Windows Defender\MpCmdRun.exe" -SignatureUpdate -MMPC

I'm currrently using it as described here:
Let your Windows 8 Defender update itself automatically.