Did you try installing the Wifi driver from the Dell site? Try Windows 10, 8.1, 8 or 7, in that order, or if necessary in Compatibility Mode.
Just because Wifi driver wasn't installed during Upgrade doesn't mean there isn't one. I've never not been able to find a driver. How to: Install and Update drivers in Windows 10 - Microsoft Community
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https://fbyellow572.weebly.com/mariner-outboard-serial-number-location.html. What is always best during OS install is to plug in by ethernet cable to maximize chances it will start up connected or a driver can be found possibly easier. Put the latest LAN drivers in your backup from the PC or Device's Support Downloads webpage so you can get online quickly if it doesn't start up ready to connect.
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Then type Update in Start Search box, Check for Updates, install all Updates including Recommended, expediting the reboot when requested. Then check again until no more are offered.
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Now right click Start button to open Device Manager, import any drivers still missing or in error from the Support Downloads webpage for your PC or the device model. https://fbyellow572.weebly.com/fcvideos-manyvids-download-torrent.html. If no Windows 10 drivers, install 8.1, 8 or 7 in that order. Some may need to be installed in Compatibility Mode.