Hello Owen,
Good day! I'm John Dev a Windows user like you and I'll be happy to assist you today. I know this has been difficult for you, Rest assured, I'm going to do my best to help you.
When was the last time it worked properly?
Please try creating a new local administrator account to see if the issue is not profile specific.
https://support.microsoft.com/en-us/windows/cre...
If the issue still persists, Please try performing an In-place Upgrade. Performing this can repair broken operating system files while your personal files, settings and installed applications will not be removed.
https://answers.microsoft.com/en-us/windows/for...
**Few things to check on the PC
Unplug all external peripherals except for the Mouse, Keyboard, and LAN cable before starting
Disable or uninstall any 3rd party Anti-Virus program to prevent it from interfering with the upgrade
Kindly let me know if this helps or if you have any further concerns.
Kind regards,
John DeV
Independent Advisor