Welcome to the forum.
Some of us hafe used Windows for years and are having a hard time with Windows 10 updates. At this point, you can try to do a recovery. But they is a catch.
The catch is that you need to install DVD or some other method to repair the computer. From what uu describe, it had gone beyound that point.
Do yu have the DVD used to install Windows 10 ?
If so, boot it up and look for a place where issays you can repair you computer.
But if you do not have the DVD or USB stick used to install winwos 10, you hare going to find it more difficult.
Look at this Goolge search answer:
Search instead for how to repai Windows 10
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Navigate to the Windows 10 Advanced Startup Options menu.
Once your computer has booted, you'll want to select Troubleshoot.
And then you'll need to click Advanced options.
Click Startup Repair.
Windows will take anywhere from a few seconds to a few minutes to attempt to fix the problem. ...
Click System Restore.
But if you never see the "Advanced Startup Options" then yhou have to fin another way to do it.
You may have to ask a fiend to prepare a USB drive with the version of Windows 10 you have. The hard part is that it has now become near imposible for the average person to know what version of Windows 10 they have. Like it is maybe a top scecret thing.
Does the computer documentation indicate what version you had? Does the maker of the computer know what you had? You should have in the documentation some way to call the support desk of the maker of the computre and find out it taht can recomend a way to recovery Windows 10 ion your computer.
Why did I not suggest you use another PC to donwload the ISO file from Microsoft.? Well, you have to know which version you had. Use the wrong version and things get worse.
Do yu have a backup of the whole systeM? If so, you might have to use it now.
EDIT: Here is more about repair of WIndows 10.
https://www.laptopmag.com/articles/repair-windows-10