Why can't I connect to wi-fi on my Window 8.1 laptop?

Have you used that router before with other computers? Have you tried turning the router off and on again? Have you tried restarting your PC? have you tried resetting your computers wireless adapter?

steps for resetting your wireless adapter are below:

Open Network and Sharing Center by swiping in from the right edge of the screen, tapping Search (or if you're using a mouse, pointing to the upper-right corner of the screen, moving the mouse pointer down, and then clicking Search), entering network and sharing in the search box, and then tapping or clicking Network and Sharing Center.

Tap or click Change adapter settings.

Press and hold or right-click the network adapter, and then tap or click Disable. Administrator permission required You might be asked for an admin password or to confirm your choice.

Press and hold or right-click the adapter again, and then tap or click Enable. Administrator permission required You might be asked for an admin password or to confirm your choice.

After you've reset the adapter, try connecting to the network again, or run the Network troubleshooter to verify that your network adapter is now working correctly.

If you could include the laptop and router model numbers that might also help determine if there's a known issue.