PPPoE Error 797 — What It Means & How to Fix It

What Does This Error Mean?

Error 797 means Windows cannot find a modem to make the internet connection. Either no modem is detected, the modem driver is missing, or the broadband connection is not configured to use the right modem. It is like trying to make a call when the phone is not plugged in.

Affected Models

Windows XP
Windows Vista
Windows 7
Windows 8
USB dongles
DSL modems
Any dial-up or PPPoE broadband connection

Common Causes

The modem driver is not installed or was uninstalled by a Windows update
A USB broadband dongle is not recognized by Windows
The broadband connection profile is pointing to the wrong or missing modem
The modem has failed to initialize after startup
A required Windows service for modem detection is not running

How to Fix It

Open Device Manager and check if your modem appears under 'Modems' or 'Network Adapters'. If it has a yellow warning triangle, the driver is the issue.

A yellow triangle means the driver is corrupted or missing.
Right-click your modem in Device Manager and select Update Driver. Let Windows search automatically.

Updating the driver often resolves detection issues immediately.
If using a USB dongle: unplug it, visit the manufacturer's website, download the latest driver, and reinstall it.

Manufacturer-supplied drivers are more reliable than Windows' generic ones for USB modems.
Open your broadband connection properties. Under the General tab, verify the correct modem is selected. If the list is empty, your modem is not being detected by Windows.

The connection profile must reference a working modem to dial out.
Restart the following Windows services: Telephony and Plug and Play. Type 'services.msc' in the Start menu to find them.

Plug and Play is responsible for detecting new hardware like USB modems.

When to Call a Professional

If the modem is physically present, correctly installed, and still not detected, contact your modem manufacturer's support line. The modem may have a hardware fault requiring replacement. Your ISP can also verify if the line provisioning is correct.

Frequently Asked Questions

Why did Error 797 appear out of nowhere on a connection that was working fine?

A Windows update can sometimes remove or overwrite modem drivers. This is a well-known issue, especially with USB broadband dongles. Check Device Manager to see if the modem still appears. If it is gone, reinstall the driver from the manufacturer's website.

Is Error 797 an ISP problem or a Windows problem?

It is almost always a Windows or driver problem. Error 797 means Windows cannot find the modem hardware. Your ISP cannot help with this — the fix is to reinstall or update your modem driver.

Can Error 797 be caused by a damaged USB port?

Yes. If the USB port your dongle is plugged into has a fault, Windows will not detect the modem. Try a different USB port on your computer. If the modem works on another port, the original port may be damaged.