Try to uninstall the driver (right clicking on it) from device manager and also from programs and features (control panel). Then, restart the computer and reinstall the driver again. You may want to download it first since you will lose connection during the process. Please download the driver from DELL’s website as they provide the customized driver for your system. You may also try our generic Intel® driver from here:
I would say the cause its related to a driver corruption but just to be on the safe side you may verify your router has the latest firmware installed.
I hope this helps.