Can't boot into Bootloader mode

[DansDesigns]

When I plug in the STM32f103 board into the USB, Windows does not recognize the device. I have the right drivers installed and it has been working but suddenly stopped.
I tried to reupload the STM32duino bootloader via the STM32 Programmer and the ST-Link but when I press KEY and NRST, nothing happens - just continues to show the power led?

Can anyone help?

[DansDesigns]

I solved the issue by erasing the first sector in flash memory, re-downloaded the stm32duino bootloader, flashed it via st-link and stm32cubeprogrammer with "Verify Programming", "Run After Programming", " Full Chip Erase" and "Download File" selected..