HOW DO GET MY NEXUS TO CONNECT TO MY WIFI - D-Link Computers & Internet

If your Tablet Nexus 7 did not connect to the internet try to refresh the connections. Open the menu and hit the settings button. Click the Wifi Off and open the page. Scan for the internet provider you are currently connected then click forget. Back to the main menu. After 10 to 20 seconds click the wifi icon and reconnect.

Reads like you've got a faulty wifi module on the Nexus. Have you got warranty?

You should be sure the wifi is turned on and set it to auto connect to wifi.

You can check with Arris ( ARRIS for Consumers ) or contact the manufacturer of your Nexus 5 for troubleshooting.

Mark
Motorola Mobility Support

I assume you're using a secure Wifi connection with a password and it seems like that authentication is not working. You could try using an open wifi access point to eliminate the possibility of this authentication issue.

Turn router off at wall switch, wait 5 minutes then restart.

Yes, after you make the connection, start your browser. The login screen comes up first after that.

(Using a WIFI Hotspot is definitely recommended. Connecting your 4G USB dongle to the Nexus 7 will drain the battery quickly since the USB is using the Nexus's battery to power on. This is what I use) but here's how to get your 4g usb dongle to work
Your device must be rooted, and you would need a USB OTG cable/adapter. Here's an example of an OTG USB cable -This app should work on any nexus 7 and it is very simple just install the app and enter your apn of your operator connect your dongles via otg cable and it will work the app available on google play store called ppp widget here is the link it is for rooted device

PPP Widget

You can connect to a free WiFi site at such places as Starbucks, MacDonalds, at some shopping centers and at the airport terminals.
Have the tablet's WiFi turned on and it will automatically detect any wireless WiFi site within range of your tablet. Some site have encryption enabled and you won't be able to connect to these wireless sites.

Are you trying to connect the Nexus to the internet via your computer? using ad-hoc wifi connection?
I followed these instructions and was able to make the connection.

Hope it helps.
Dan