Be sure not NOT use the provided Dell Update utility (you'll see it running in your system tray on Desktop.)
That Dell Update utility will download a driver update for the screen that will cause the tablet to be unable to boot, necessitating image restore to factory.
If you haven't done so already, create USB flash drive factory image backup.
Then update through Charms bar: swipe from right edge of screen, select Settings, then Change PC settings, then Update and recovery. It's best you connect through wired Interne connection through USB OTG cable if possible as the amount of updates will be quite large and take quite some time to install.
Once that's completed. Register your tablet on the Dell support site. Download and install the updates for BIOS and wireless/Bluetooth.