Here are some steps you can try to resolve the issue:
- Restart both the router and the laptop.
- Update the wifi drivers on your laptop.
- Disable and re-enable the wifi adapter in Device Manager.
- Make sure the wifi switch on your laptop is turned on (if your laptop has one).
- Reset the network settings on your laptop to default.
- Try to connect to a different wifi network to see if the issue is specific to your D-Link router.
If the above steps don't work, you could try a factory reset. However, keep in mind that doing a factory reset will erase all data on your laptop and restore it to its original state. Make sure to backup any important data before proceeding with a factory reset.