If you open up Device Manager
is there any devices with a yellow exclaimation mark next to them?
Is so then try removing/uninstalling the device, rebooting then Windows will re-install the drivers
If not then you might want to re-boot your router.
Normally to reboot just switch the machine off, locate a small hole and press a pen into it for 5-10 seconds then power on the machine. For more information please consult your router documentation.
If your ISP has sent update data to the router it can cause connectivity issues that would seem to be caused by your computer/laptop and normally a re-boot fixes these isues