What Hardware version is your router? Look at sticker under router.
What Firmware version is currently loaded? Found on routers web page under status.
What ISP Service do you have? Cable or DSL?
What ISP Modem do you have? Stand Alone or built in router?
What ISP Modem make and model do you have?
If this modem has a built in router, it's best to bridge the modem. Having 2 routers on the same line can cause connection problems.
Some things to try:
Ensure DNS IP addresses are being filled in under Setup/Internet/Manual? You can find these under Status/Device Info/Wan section.
Turn off ALL QoS (DIR only) GameFuel (DGL only and if ON.) options. Advanced/QoS or Gamefuel. We can set this back up later. Come visit us in the DGL-4500 forum. Good info here on XBL.
Turn off Advanced DNS Services if you have this option under Setup/Internet/Manual.
Turn on DNS Relay under Setup/Networking.
Setup DHCP reserved IP addresses for all devices on the router. Setup/Networking
Ensure devices are set to auto obtain an IP address.
Set Firewall settings to Endpoint Independent for TCP and UDP.
Disable Super G mode and just run standard G mode
What security mode are you using? Preferred security is WPA-Personal. WPA2/Auto TPIK and AES or AES only.
What wireless devices do you have connected?
Any cordless house phones?
Any other WiFi routers in the area? Use
InSSIDer to find out.
Disable WDS under Advanced Wireless.
Turn off all anti virus and firewall programs on PC while testing. 3rd party firewalls are not generally needed when using routers as they are effective on blocking malicious inbound traffic.
Turn off all devices accept for one wired PC while testing.
Check cable between Modem and Router, swap out to be sure. Cat6 or 5e is recommended.
Possible that the wireless could be faulty however lets see if we can do some troubleshooting. If anything you could get a DAP-1525 and connect to the 4300 and that can be your new wireless. Just turn off the radio on the 4300.
Maybe someone can review your router settings with you using
teamviewer.Let us know.