> Model: A7000|Nighthawk AC1900 WiFi USB Adapter - USB 3.0
Not a router. Look for "Model" on the product label. Firmware version?
> Lost signal [...]
What does that mean, in terms of actual observables?
> [...] while trying to update
"trying" _how_?
> [...] don't know where to start [...]
Describe what you did? Describe what you see?
> [...] and failed
Which kind of "failed"?
Visit http://netgear.com/support , put in your (actual) model number, and look for Documentation. Get the User Manual (at least). Read. Look for the LED descriptions and "Troubleshoot".
If you have a flashing power indicator, then you may be a candidate for the TFTP recovery scheme. See, for example:
