problems staying on the internet

Just like alot of people, i also have the problem with staying connected to the internet. I troubleshoot, and it says "the default gateway is unavailable". At first it was only happening when my wife would be on her laptop and I would be on mine watching netflix. Talking to the isp (time warner) and even the router company (Belkin n300 router) didnt help. Belkin had us change the channel on the router and do a few other things but its still disconnecting randomly. Ive had this netbook for over a year now and any other time I havent had problems staying connected to the internet. Just last month before getting the internet I upgraded from 7 starter to ultimate. Thats the only change that has happened to my netbook that I can see. It disconnects when its wireless and wired. Ive uninstalled and reinstalled and updated the driver so its not that.
here is what the ipconfig says while im connected
Windows IP Configuration

Host Name . . . . . . . . . . . . : lunchbox-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : Belkin

Wireless LAN adapter Wireless Network Connection:

Connection-specific DNS Suffix . : Belkin
Description . . . . . . . . . . . : Atheros AR5B95 Wireless Network Adapter
Physical Address. . . . . . . . . : 90-4C-E5-43-03-F6
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::35fd:e3fc:ac28:e8fc%15(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.2.3(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Monday, July 25, 2011 3:07:16 PM
Lease Expires . . . . . . . . . . : Thursday, August 31, 2147 10:00:07 PM
Default Gateway . . . . . . . . . : 192.168.2.1
DHCP Server . . . . . . . . . . . : 192.168.2.1
DHCPv6 IAID . . . . . . . . . . . : 345001189
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-15-91-76-53-70-5A-B6-09-A4-18

DNS Servers . . . . . . . . . . . : 192.168.2.1
NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Local Area Connection:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Atheros AR8132 PCI-E Fast Ethernet Contro
ller (NDIS 6.20)
Physical Address. . . . . . . . . : 70-5A-B6-09-A4-18
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter isatap.Belkin:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : Belkin
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:c27:1dc:9de3:a915(Prefer
red)
Link-local IPv6 Address . . . . . : fe80::c27:1dc:9de3:a915%11(Preferred)
Default Gateway . . . . . . . . . : ::
NetBIOS over Tcpip. . . . . . . . : Disabled

Hi agadida, welcome to seven forums. From your system spec, you just meet the requirement spec for windows 7. What programs are running when you have this problem crop up? I am thinking that maybe, you are running short of available RAM and a task maybe starting that causes a glitch?. You could try putting in an SD card and using it as "readyboost", if the problem goes away, you can then decide if you want to replace the SD card with a RAM stick.

Sometimes its just chrome internet explorer, and i have Microsoft Security Essentials running. Anything else is whatever is normally running in the background automatically. I'll try that and report back with my results. Thank you for getting back with me with a suggestion.