Windows Error 651 — PPPoE Connection Failed

Windows network error 651 means the modem or connection device has reported an error during a PPPoE connection attempt. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Connection failed with error 651 — PPPoE dial-up error. Common with DSL and fiber connections using PPPoE. Affects the RAS (Remote Access Service) component. May require modem or router restart. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: ISP connection issues or outage. Corrupted raspppoe.sys driver file. Network adapter misconfiguration. Modem or router firmware issues. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Restart modem and router — wait 30 seconds between. Delete and recreate the PPPoE connection. Replace raspppoe.sys from a working Windows installation. Disable IPv6 on the network adapter. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Windows Error Codes collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.