You can set up the router manually using the routers web page.
Some info to try:
What ISP Modem do you have? Stand Alone or built in router?
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.
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.
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.
Ensure devices are set to auto obtain an IP address.
Set Firewall settings to Endpoint Independent for TCP and UDP.
What wireless modes are you using?
Try single mode G or mixed G and N?
What security mode are you using? WEP, WPA or WPA2? Preferred is WPA-Personal. WPA2/Auto TPIK and AES.
If you need additional help, maybe some one can use
teamviewer.com and review your settings with you.