The process of setting up a modem/router in your Internet service requires making various changes to the settings. These may not be the same as the settings you need for a new service.
If you know exactly what you are doing, and what settings you need to change, you may be able to do it manually.
But it is often easier to put the modem/router back to its "out of the box" state.
Another option might be to run the setup wizard again.
There is support for the D7000, including a manual, somewhere at the end of this link:
>>> D7000 | Product | Support | NETGEAR <<<
See the section in the manual Use the Internet Setup Wizard After Initial Setup.
What you cannot do is simply unplug one Internet service and rep[lace it with another one and expect everything to go smoothly.
This still may not fix your problem, but it is likely to be the first suggestion from support people.
In your first message you say:
The modem disconnects from every wifi connection and at teh same time it continues to broadcast but didnt accept any device until I hit reset.
This does not make sense.
The modem does not disconnect from wifi connections. It will be the other way round. Wifi clients will disconnect from the wifi source, the router.
And what does "hit reset" mean?
For better advice, explain exactly what is going on, the steps your are taking and what goes wrong.
