How I Fixed Windows Installation - BitLocker, a Write-Protected USB, and the IRST Rabbit Hole

Friend's HP laptop locked behind BitLocker — no recovery key, no choice but to reinstall Windows. Three things broke in sequence: USB write-protected — FAT32 format was the culprit. Fixed with diskpart clean and reformatting as exFAT.SSD invisible to the installer — HP's 11th-gen Intel processor needs IRST drivers the Media Creation Tool doesn't ship with. Downloaded from HP Support, extracted the F6 folder, loaded iaStorVD.inf during setup.Install froze at 15% — FAT32's 4 GB file size limit chokes on install.wim. Reformatted the USB as exFAT, reran MCT, repeated the IRST steps. Done. The fix that solves all three upfront: always format your USB as exFAT before running Media Creation Tool, and keep the IRST F6 folder on the same drive.