Tue Oct 16, 2018 10:12 am
It's not likely that Defender virus protection is your problem as suspect software is quarantined and remains so whether Defender is running or not; however, there may be other Windows security features, such as the firewall that are toggled when you turn it off.
I'd start by having a look at the Firewall settings. Even though the firewall is associated with network traffic, it could be interfering with your device driver, especially if the driver is attempting to go out on the network to check for updates. Also, make sure that all of the firewall notifications are turned on so you can see what it's doing.
You also might want to have a look at other security settings such as Device Security and App & Browser control for possible clues. Finally, check Device & Performance Health, also under the Control Panel Security settings for driver issues.
It's also worth pointing out that just because your machine is not connected to the Internet it does not mean it is safe from viruses. Computer viruses are transmitted via software. The Internet is the most common vector for software viruses, but disks, USB drives, and virtually anything you connect your computer to can infect it, so it's wise to always have some sort of protection in place.