The X would seem to means your wireless adapter or what it is connecting to is not working. If you know your router is working, check the wireless adapter. Type ncpa.cpl in a Run box to open the connections dialog. From there you can try diabling and then re-enabling the adapter. If that doesn't work you can use some of the other options to Diagnose or see what type of IP address it is picking up.
In some instances, manually adding an IP address will "prime the pump" and allow for the adapter to find its own IP address when you go back to automatic.
If none of this works, you might need to uninstall the device in Device Manager and then reinstall the driver. Make sure you have a current driver for the device downloaded and then uninstall the adapter and check the box to uninstall all drivers. Windows may try to load its driver, but if you can get your Win 10 driver loaded, it may go back to normal functions.
Can you tell us the make and model of the computer or the Wireless adapter installed?