Dell XPS Desktop won't connect to internet through LAN or Wifi Adapter

Hey all,

I've been away from the PC world for the past few years because I've been running a Mac.
I decided to get back into some gaming on picked up a Dell XPS desktop running windows 7 ultimate x64.
I bought a Asus USB N10 Wifi Adapter and it won't connect to the internet. It gets a limited activity logo over top of the connection.
Today I tried plugging it rite into the router with a LAN cable and still, no dice. Came up with an IP address error.
I'm guessing this is a router issue? When i run ipconfig in cmd prompt, it doesn't even have a default gateway?
Could someone explain what is going wrong here, and why It wont connect? We have 2 Macs, a PS3, some android tablets and a HP laptop running from out D-Link router.

Thanks for the help in advance, I really appreciate it guys!

Lemur,
They are all up to date.
Now when I try to connect to my router is says "Windows cannot connect to XXXXX"
Even when i try to connect to my iPhone wifi hotspot it says "Windows cannot connect to XXXXXX"
Under network adapters there are two wifi ones. "Asus EZ" and "Microsoft Virtual Wifi Miniport" not sure if that means anything?

Any other ideas?
Thanks!

Can it have effect if your network services are not set to auto-start, such as DHCP ? So check your services in Control Panel, Administrative Tools maybe.

OK
So since disabling the Wifi Miniport adapter, when i setup a hotspot from my phone, the computer WILL access the internet. However when trying connecting to my home network, it still wont connect.
So its something to do with the communication between my router and my PC?
Any ideas guys?
I appreciate the help so far!

Do you guys have any other ideas? It seems like its an issue between the computer and router bc my computer will connect to to my hot spots from my phones.
My computer wont even obtain a default gateway from the router?
Thanks guys

Just in case any of you have just come across this recently... like me ... I found that the latest McAfee patch was my problem. I was able to access the internet via safe mode with networking (choose F2, then F8 to choose this on start up). I then went to the Dell site and noticed that they were aware of the issue. The have a support topic "Software Updates Causes Wireless Connectivity issue or Unable to Connect to Internet". I was able to work through their fix (via the McAfee Virtual Technician) in Safe mode and I'm relieved to say that it is now running fine...phew.