Hi Alexsh16,
Please update the wireless drivers from the link http://dell.to/11vrVoB. Also, update the BIOS of the system from the link http://dell.to/14i9ghO. Once the system restarts after the BIOS update, check functionality.
Note: Make sure the ac adapter is connected and the battery is charged 10% or above to update the BIOS. Also, disconnect all the external peripherals before updating the BIOS. All the programs should be closed and documents saved.
Hope this helps. Please reply if you have any questions.