Hello Daveglooo.
Welcome to Microsoft Community!
I'm sorry to hear that your computer is unable to boot, you mentioned that you tried everything but were unable to get into safe mode, in which case booting from a USB flash drive would have to be the most effective option.
To boot from a USB flash drive, you need to create the installation media for the USB flash drive, see Create installation media for Windows - Microsoft Support.
Connect the created USB flash drive to your problematic computer and enter the BIOS to set the USB flash drive containing Windows as the preferred boot item. For specific steps on this, you need to check according to the brand of your device.
- After entering the Windows installation program on the USB flash drive, you will need to select the language information, and when you are done, click Next.
- On the installation page, select Repair your computer in the lower left corner.
- On the next screen, select Troubleshoot and then select Advanced options.
- If you have set up a system restore point, you can choose System Restore, if you have not set up a restore point, then you can try to start the repair, then follow the instructions and the system will automatically complete the repair.
If the repair still cannot be completed, you may need to reinstall Windows.
Please note that although some reset options may offer the option to keep your files, you are still at risk of losing your files, so make sure that you are okay with these files being deleted from your computer when performing subsequent actions.
- Reboot your computer to access the USB flash drive, or select "Advanced options" on the previous failed repair prompt page to go back to the previous page. In the Troubleshooting section, select "Reset this computer", through which you can choose to keep or delete your personal files. Alternatively, you can reinstall Windows directly from the installation program on the USB drive.
You can also refer to these article for detailed steps :
How to: Perform a Custom Installation of Windows 11 and Windows 10 or - Microsoft Community
Windows 10 "Repair your computer" "Reset this PC" Screens - Microsoft Community
If you have any questions, please feel free to contact us, so that we can offer you further assistance.
Best Regards,
Eliac | Microsoft Community Support Specialist