Yes, that's attempted to upgrade from W7 back to W10 CU (v1703) and that does not work 100% of the time. Hopefully, by this time you backed up all your personal data to external media, as if you haven't it's all gone now!!
It would be helpful to know the exact version of W10 you had or have. The latest W10 update I'm mentioning came out last Tue. April 11th and the 2 upgrade attempts I made only 1 of 2 worked. The update attempt on my W10 Pro desktop worked fine. The 2nd one on a Dell Optiplex 745 failed 5 times, and on the very same update KB4015438. That you cannot fix as it's an apparent flaw in the W10 installer program (Update Assistant). Just reporting that failure this morning here. Already reported it to Microsoft. They don't acknowledge it's a problem. The only solution available to you is to go to Microsoft's website and download the free MCT tool and create a bootable W10 install media either or DVD disk or USB stick available here:
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If you cannot achieve this on your computer, you should consider taking it to your local Computer repair shop and paying a Tech to do this for you.
He may also encounter failed components in your laptop, which he can give you a written estimate on cost to replace while doing your upgrade. It's also possible that your built-in WLAN card (or Wi-Fi chip) has failed and that's why your browsers have all failed to work properly on the Wi-Fi Internet connection.
Once you get your W10 installed; any version doesn't have to be the new one (v1703), and your Wi-Fi fails to work still, you can borrow or buy an inexpensive Wi-Fi USB adapter for
$60 US or so, plug that into your laptop and it will fix your problem even if your internal WLAN card is borked! Bear in mind the WLAN card is a $10 part, but at least a $100 in labor to remove it in many laptops as the laptop has to be completely disassembled to replace the part, so days of labor there. If that's the case, you can save at least half the repair cost by using a USB plug in adapter to solve the problem. The inconvenience is you have to remember to put that in your laptop case and take with you if you ever leave your house with your laptop and expect it to work on any wireless network.
Here's an example of a recommended USB Wi-Fi adapter that I use:
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