Oh my… That kind of mess shouldn’t have happened.
Let me suggest some things to try with the router.
Since it was running in it’s default configuration before all this happened, then the easy way to restore that original factory setting is to press the “reset” button on the back of the router. As described in the D-Lnik manual, page 14:
Factory Reset Button
The Router may be reset to the original factory default settings by depressing the reset button for a few seconds while the device is powered on. Use a ballpoint or paperclip to gently push down the reset button. Remember that this will wipe out any settings stored in flash memory including user account information and LAN IP settings. The device settings will be restored to the factory default IP address 10.1.1.1 and the subnet mask is 255.255.255.0, the default management Username is “admin” and the default Password is “admin.”
As the default seems to have been to run as a bridge, then that should get you back to being a bridge. That’s assuming that no one had explicitly set up a bridge. In my experience, routers come up as routers, not as a bridge
The router does have some diagnostic tools that can tell you if it is properly connected. If the router diagnostics say something isn’t right, then whatever your PC is configured as doesn’t matter. The router has to be working first, then move on to the PC setup.
On the router, there is a “Tools” tab, there is a “Test” button. This will give you a pass/fail test on the network connectivity to your ISP. If you get a fail, then something needs to be changed in the router setup.
Once everything is a pass, then use the ping test on “Tools”, “Miscellaneous”. This will check that your have an actual working Internet connection. I use www.google.com as a test (IP address of 72.14.205.147). If you get answers back, then you’ve got a working Internet connection.
If things are working on the router at this point, your router is properly configured. Whether your PC is set up properly is the next question. One thing at a time first, and right now that’s the router.