Windows defender offline says out of date on one computer but is up to - Microsoft Community

Windows defender offline says out of date on one computer but is up to - Microsoft Community

Sometimes you need to run a virus scan at boot time. So Microsoft created Windows Defender Offline: Use an uninfected PC and a blank USB stick to create a bootable USB stick, then boot the infected PC from the USB stick. (You may need to change your BIOS boot order to make this work.) A scan runs from the USB stick, without anything on the infected drive allowed to run.

Here's the rub: The special Windows install on the stick doesn't include a USB3 driver, so while it can boot with the USB stick in a USB3 port, the software can't find the virus definitions. The fix is to boot with the USB stick in a USB2 port.