I'm assuming by this point you are getting frustrated and worried about this issue, but I know we can get you back running. Let's just continue troubleshooting. I did a search for the file you mentioned, econt_Vision-AV2000 and found a few threads with people that ran into the same or similar issue.
Here is one. Just glancing real quick at the threads, some were able to fix the problem by continuing to power cycle the NVR until it finally connected to the
TFTP server. Others were able to use iVMS to connect to the NVR and initiate a device factory reset from there until it finally took.
Have you tried connecting to the NVR via browser? You know, 192.168.1.170 in browser window? Are you able to see the login page? When I originally had the problem, my IP address and gateway were 0.0.0.0, so my only option was to go directly to the NVR.