Problems connecting to a network at a distance from router

[KPAN]

Hi TechSupport!
I'm having problems connecting to my home wireless network on my Dell XPS L502X (or XPS 15) bought 2 days ago. I can connect only when I'm around a 3 meter radius of my wireless router, but anywhere farther than that causes disconnection. My wireless router is a D-link model DIR-615. My other laptop, a Dell Inspiron and my Desktop have no problems connecting.
Thank you in advance ^^

[KPAN]

I also forgot to mention that even though my signal strength is strong, it still doesn't allow me connect or reconnect to a network.