If your goal is simply to unlock a bootloader, flash a custom recovery like TWRP, or sideload an OTA update, the full SDK is overkill. gives you exactly what you need and nothing more.
Once installed, you can perform several advanced tasks directly from your PC: minimal_adb_fastboot_v1.4.3_setup.exe - Android File Host minimal-adb-fastboot-v1.4.3-setup
This is the most overlooked step. Your computer must recognize your phone before ADB or Fastboot can talk to it. If your goal is simply to unlock a
Minimal ADB and Fastboot v1.4.3 does include USB drivers—by design. You must install your phone’s specific USB driver separately. flash a custom recovery like TWRP
If the screen is broken but the device powers on, adb pull /sdcard/DCIM/ ./ can save your photos.