How to fix Error 768 on Windows 11

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Windows 11 Error 768: Exception in User Mode Callback

Why This Error Happens

Error 768 occurs when a kernel-mode routine calls into user-mode code (a callback), and that callback throws an exception that isn’t properly handled. This is typically triggered by corrupted system files, an incompatible or outdated driver (especially graphics, audio, or input device drivers) mishandling a callback frame, or memory corruption caused by faulty RAM or a failing storage drive. Since this is a kernel-level event, third-party drivers that hook into Win32k.sys or User32.dll are the most common culprits.

Step-by-Step Resolution Guide

  1. Check Event Viewer for the source:
  • Press Win + X → select Event Viewer.
  • Navigate to Windows Logs > System, filter by Event ID 768.
  • Note the exact source module (often listed in the “Details” tab as a .dll or .sys file) — this identifies the faulty driver.
  1. Update or roll back the identified driver:
  • Open Device Manager (Win + X → Device Manager).
  • Locate the device tied to the faulty driver (commonly Display adapters or Human Interface Devices).
  • Right-click → Update driver. If the issue started after a recent update, instead choose Properties > Driver > Roll Back Driver.
  1. Run System File Checker and DISM:
  • Open Command Prompt as Administrator.
  • Run: sfc /scannow
  • Then run:

    DISM /Online /Cleanup-Image /RestoreHealth
  • Restart your PC after completion.
  1. Test physical memory (RAM):
  • Press Win + R, type mdsched.exe, and press Enter.
  • Choose Restart now and check for problems.
  • If errors are found, reseat or replace the faulty RAM module.
  1. Update Windows fully:
  • Go to Settings > Windows Update > Check for updates.
  • Install all pending updates, including optional driver updates, then restart.

Alternative or Verification Steps

  • Verify the fix: Reopen Event Viewer and monitor the System log for 24–48 hours to confirm Error 768 no longer appears.
  • Alternative fix: If the error persists, boot into Safe Mode (Settings > Recovery > Advanced Startup > Restart Now) and check if the error recurs — if not, a third-party driver or startup app is likely the cause, and a clean boot troubleshooting process should be used to isolate it.