I found another way using the registry.
Using this articlethis article, I changed the startup type for the Defender services and drivers (!!) in the registry while logged on as an administrator. Here's a brief run-down:
- Browse the registry to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
. - Look for services starting with "wd" that have "Windows Defender" in the Description value. A possibly incomplete list is: wdboot, wdfilter, wdnisdrv, wdnissvc, windefend.
- Change the
Start
value for each service to0x4
(hex 4, decimal 4). - Reboot.