pixelwanker When you initially ran the install, the install did not complete either because your USB connection dropped, or because you have too little space on your PC. You need at least 32 GB free space on your PC.
On your phone, in developer options disable USB debugging if you have it enabled (that's not required), and make sure OEM unlocking is still enabled.
Make sure you have at least 32 GB free space on your Windows PC. Open the web installer in either Chrome or Edge. If you're using Brave, disable Brave Shields.
Reboot your phone into the bootloader interface, and then connect the phone and your PC with the OEM USB-C to USB-C cable that came with your phone.
If you uninstalled the fastboot drivers from your PC, install them again. Do that by checking only now for optional Windows updates.
Then proceed in the web installer from the Download release step. Once that's completed press Flash release. The phone will restart multiple times, a couple of times into fastboot mode, once into fastbootd, and then finally back into fastboot mode. You'll see in the web installer when the flashing has completed.
If you continue to face issues, please join us on Discord or Matrix, and we'll help walk you through the install.
The important part is not to interrupt the install from your phone. If flashing fails or the USB connection drops, simply keep your phone in fastboot mode, and flash release from the web installer once again.