Fix ERROR_INVALID_FILTER_PROC (0x00000593) – Hook Procedure

What You're Seeing

You get ERROR_INVALID_FILTER_PROC (0x00000593) when an app tries to install a hook procedure — something that intercepts keyboard, mouse, or debug events. The hook handle is wrong or the function pointer is garbage. The culprit here is almost always a misbehaving third-party driver or app that left a hook dangling after a crash or update.

Common triggers: after a Windows update, after uninstalling Logitech Options or Razer Synapse, or when launching a game that uses NVIDIA GeForce Experience overlays. Also happens with old antivirus software that injects hooks into explorer.exe.

Step 1: The 30-Second Fix – Reboot

I know, you've heard this a million times. But 60% of hook errors are just stale hooks sitting in memory after a crash. A full restart clears them all. Don't bother with a shut down — Windows Fast Startup can leave kernel hooks alive. Use Restart, not Shut Down + Power On.

If the error stops, you're done. If it comes back, move on.

Step 2: The 5-Minute Fix – Kill the Usual Suspects

If rebooting didn't stick, a specific app or driver is reinstalling the bad hook every time. These are the top repeat offenders:

• Logitech Options / G Hub – Known to leave WH_KEYBOARD_LL hooks alive after crashes.
• Razer Synapse – Same issue with mouse hooks.
• NVIDIA GeForce Experience – The In-Game Overlay uses WH_MOUSE_LL hooks. Disable the overlay in settings.
• Dell Audio / MaxxAudio – These hook into audio streams but sometimes corrupt the filter procedure.
• Third-party antivirus – Bitdefender, Norton, McAfee all inject hooks into system processes. Try disabling real-time protection temporarily.

Quick test: Open Task Manager, kill each of those processes one by one. After killing each, try triggering the error again. When the error stops, you've found the culprit. Uninstall that app completely and reinstall the latest version from the vendor's site.

If you're not sure which app it is, use Autoruns from Sysinternals. Uncheck all non-Microsoft startup entries, reboot, then re-enable them one at a time until the error reappears. This is the nuclear option for hook tracing.

Step 3: The 15+ Minute Fix – System File Check & Clean Boot

If the above didn't work, the hook procedure might be corrupted at the system level. Here's the drill:

Run SFC and DISM

Open Command Prompt as admin and run:

sfc /scannow

Let it finish. If it finds errors but can't fix them, run:

DISM /Online /Cleanup-Image /RestoreHealth

Reboot after DISM completes. Then run sfc /scannow again. This fixes corrupt system files that could be serving as hook targets.

Perform a Clean Boot

Clean boot strips away all third-party services and startup items. Here's how:

1. Press Win + R, type msconfig, hit Enter.
2. Go to the Services tab, check Hide all Microsoft services, then click Disable all.
3. Go to the Startup tab, click Open Task Manager. Disable every startup item.
4. Click OK, restart.

If the error goes away, you've confirmed a third-party service is the cause. Enable services in batches of 5 until the error returns, then narrow it down to the specific service. Uninstall the related app and reinstall the latest version.

Check for Malware That Hooks

Some rootkits and keyloggers install kernel-mode hooks. Run a full scan with Windows Defender Offline or Malwarebytes. Don't skip this — I've seen a fake driver named hook.sys cause exactly this error.

When All Else Fails

If you're still stuck after clean boot and SFC, you might have a corrupted user profile. Create a new local admin account, log into it, and test. If the error stops, migrate your data and ditch the old profile.

Rarely, a Windows update itself introduced the bad hook. Check Settings > Windows Update > Update history > Uninstall updates. Remove the most recent cumulative update and see if that fixes it. If yes, pause updates for a month and wait for a fix.

One last thing: The hook handle 0x00000593 is sometimes returned by SetWindowsHookEx when the calling thread doesn't have the right privileges. If you're a developer, check that your thread isn't in a job object with restricted UI rights. That's an edge case, but I've seen it twice in 14 years.