It’s probably not Intel’s HAXM that fixed the issue, and simply ‘Turning hyper-v ON then OFF again’ almost certainly didn’t fix it, my money is on a bug in his antivirus’ VT-x babysitting module.
TL;DR scour your antivirus software for options relating to ‘VT-x’, ‘VT-d’, ‘Virtualisation’ and/or ‘virtual machines’ and disable any options you may find that reference these.
EDIT: You also haven’t told us what your pc’s specs are. You need a reasonably strong PC to run games on NOX flawlessly. Little netbook with a twin core CPU and integrated GPU probably won’t cut it.
i have an alienware m17 so my laptop should normally be able to handle it. I looked for the enable hardware assisted virtualization but could not find it in my norton antivirus
and this is what i got when i clicked on the red ! https://gyazo.com/b91f0c3be793b73874674e4bf4c4ca16