My laptop will connect to internet using Ethernet cable but not Wi-Fi?

I know its not our provider because we've paid everything off. I have a Netgear modem and I don't think its that because my Xbox 360 connects to the internet my iPhone does too, just not my laptop(Dell Inspiron Windows 7)! I've been able to connect wireless before. I diagnosed it and it said Windows can't communicate with dns server. I've been on Microsoft and that didn't help. Anyway I can fix this? I have no clue what the ip address is or dios or any of that, so please be specific. If it is my router is there anyway I can fix that? Sorry if the picture is too small

I'm Shuchi from the Dell Social Media outreach team.

In order to enable the Wi-Fi please press the Fn and F2 button together.

Turn off the modem, router and the system. First turn on the Modem, then the router and then the system.

Please download the Wi-Fi driver:

http://dell.to/...to/17MvbiM

Enter the Service Tag and press submit button. ( You can find the service tag at the bottom of the laptop on white sticker, it's a seven digit alphanumeric code which ends with BS or number 1.)

Chose the Operating system.

Click on the Network and download the Wi-Fi drivers depending upon the Network card that was shipped with your system.

Please visit following Video for more information regarding the same:

http://dell.to/...to/1id2pxI

For more information on wireless troubleshooting please click on the following link:

http://dell.to/...to/15IxJOG

In case you have any further issue or you need any assistance please revert to this post. We will be really glad to assist you.

We would recommend you do not post your private information on a public forum.

Thanks & Regards
Shuchi S
#iworkfordell
(You can now follow us on you tube for online video support http://dell.to/...o/13ijS47)