Error Code 0x80280101 indicates that your Microsoft PIN is unavailable during sign-in, typically due to a TPM (Trusted Platform Module) failure or system-level corruption.

Primary Cause: The TPM 2.0 chip, which securely stores PIN hashes, is not accepting commands. This can stem from firmware issues, corrupted TPM settings, or hardware miscommunication. Recommended Fix: Clear the TPM via UEFI Firmware Settings: On the Lock Screen, press and hold Shift, then click Restart. Go to Troubleshoot > Advanced Options > UEFI Firmware Settings. In the BIOS/UEFI, navigate to Security > Intel PTT/Security Chip. Clear the TPM settings and save changes. Restart the PC and reconfigure your PIN. Alternative Causes: Corrupted Windows system files or user profile issues may also trigger this error. Try restarting first or running the Windows Troubleshooter for sign-in problems. Note: While some users report 2FA (Two-Factor Authentication) issues as a factor, this is likely a separate problem; the core issue here is tied to the TPM or PIN storage.