Laptop says signal strength is excellent, but

Hello,
I'm running windows 7 64bit and have had WiFi connection before on an older D-Link.
I now am using a newer 655Dir router.
My laptop shows (Toshiba) that I am connected with Excellent Strength, but I CAN'T CONNECT!!!
This has been going on for months now and it is driving me crazy!
I have IE and Firefox 11 both installed.
All my other devices connect "sometimes".
I'm beginning to think it's my router.
I use Asahi-net with AU Hikari.

Just checked connectivity and "IPv4 and IPv6 now have no connectivity. Just minutes ago I had Internet through IPv4 only.
Now "Default Gateway is not available" I am connected directly to the Hikari modem.
All lights are a go also on the Modem, Home Gateway from AU and on my D-Link.

And YES, I have unplugged, replugged and restarted everything multiple times.

This is my first Discussion that I have ever joined and my first question. Please bear with me. I am pretty much computer illiterate!

Any advice would be greatly welcomed.
Thanks