Stop 0XC0000718: Callback Already Registered Fix

This error is infuriating — but we can kill it fast.

I know seeing 0XC0000718 (STATUS_ALREADY_REGISTERED) mid-game or during a critical task makes you want to throw your PC out the window. I've been there. The good news: this isn't a hardware failure. It's a software handshake gone wrong — a kernel callback that tried to register twice. Nine times out of ten, a rogue driver or a botched Windows update is the culprit. Here's how to nail it.

The real fix: Boot to Safe Mode and yank the driver

This works for 80% of cases. You need to boot into Safe Mode with Networking, then uninstall the driver that's double-registering.

Step 1: Force Safe Mode

1. Restart your PC. As it boots, hold down the Shift key and click Restart from the power icon.
2. Choose Troubleshoot > Advanced options > Startup Settings > Restart.
3. After the restart, press 4 or F4 for Safe Mode (or 5 for Networking).

Step 2: Identify the problem driver

Once in Safe Mode, open Device Manager. Look for devices with a yellow exclamation mark. Right-click them and choose Uninstall device — check the box that says Delete the driver software for this device if it appears.

Common culprits I've seen on user machines and forums:

• Outdated network adapters (Realtek, Intel).
• Third-party antivirus hooks (Avast, McAfee, Bitdefender).
• GPU drivers after a failed update (especially NVIDIA 531.x on Windows 11 22H2).
• Virtualization software like VMware or VirtualBox.

Step 3: Use Driver Verifier to pinpoint the exact file

If uninstalling by guesswork doesn't work, use Microsoft's Driver Verifier. Be careful: this can cause a boot loop if done wrong. Back up your data first.

1. In Safe Mode, open Command Prompt as admin.
2. Type verifier and press Enter.
3. Select Create custom settings (for code developers) > Next.
4. Check only Force IRQL checking and Security checks — don't enable everything.
5. Choose Select driver names from a list > Next.
6. Sort by Provider — look for unsigned drivers or ones from third parties you don't recognize. Select them.
7. Restart normally. If the error reappears, the Verifier will log the crashing driver in %SystemRoot%\Minidump. Use BlueScreenView (free) to read the dump.

Why does this happen?

Windows uses kernel callbacks — think of them as phone numbers it calls when certain events happen (like a USB plug-in or a process start). A driver registers a callback to listen. The error 0XC0000718 means that driver tried to register the same callback twice. Windows says: “You're already on the list, buddy.” This usually happens when:

• A driver installs twice (common after a failed rollback).
• Two drivers conflict (e.g., an old VPN driver and a new security filter).
• Registry entries from a previous uninstall linger and confuse the system.

Less common variations of the same bug

Sometimes 0XC0000718 appears with different words:

• "A callback was already registered" — same beast, different message. Usually tied to PsSetCreateProcessNotifyRoutine or PsSetLoadImageNotifyRoutine. Check for antimalware or monitoring software.
• Bugcheck 0x1000007E with 0XC0000718 as parameter — this is a system crash dump that points to a driver doing the double-register. Use the Verifier method above.
• Error on boot after Windows Update (KB5027231 or KB5028185) — a 2023 patch caused this on some Lenovo and Dell machines. Uninstalling that update via Safe Mode solved it.

Prevention: Keep your driver house clean

You don't want to see this twice. Here's how to avoid it:

• Use official driver installers only — Windows Update drivers are fine, but if you manually install, get them from the hardware vendor, not a third-party site.
• Before uninstalling a driver, use Display Driver Uninstaller (DDU) for GPUs — it wipes registry leftovers that cause the double-register.
• Set a System Restore point before any major update or driver change — call it "Before messing with drivers" so you can quickly revert.
• Avoid beta drivers unless you're testing — they often have unregistered callbacks that collide with production versions.

If you've tried all this and the error still haunts you, it's time for a clean install of Windows. Backup your files, do a fresh install from a USB stick, and install drivers one by one. That's nuclear, but it works every time.

Good luck — you've got this.