Update per Dell-Cares; To fix this, please follow the below steps: Restart your system and enter the BIOS by pressing repeatedly the F2 key during the POST screen (Dell Logo) Once inside the BIOS, hit the F9 key to restore "Setup Defaults".  Restart your system once more. Check your system's product page (link to Vostro 5402) and download the latest BIOS and Wireless Driver. Install both and restart the system when requested. This should resolve the issue. 
I have a Dell Vostro 5402, Os: Windows 10 Pro and I am experiencing an issue: the current wireless connection gets disconnected when I plug in any USB device and my wireless networks doesn't appear in the list anymore to try to reconnect with the network.When I unplug the USB device my wireless network appears in the list and reconnects automatically.Please help me with a solution. I have tried different advices I have found on Dell community but nothing works.  
Dell vostro 5402 wireless network disconnects while USB device is plugged in