Windows BSOD Error 0x00000033 — What It Means & How to Fix It

What Does This Error Mean?

BSOD 0x00000033 (UNEXPECTED_INITIALIZATION_CALL) means a kernel component or driver was called at the wrong time during Windows startup — before it was fully initialized and ready to handle requests. This is almost always a driver compatibility problem. It often appears after a driver update, new hardware installation, or a Windows upgrade.

Affected Models

Windows 10
Windows 11
Windows 8.1
Windows 7

Common Causes

A newly installed driver is being loaded before its dependencies are ready during boot
A driver update broke the correct initialization order that Windows expects
Corrupted Windows boot files are causing startup components to load in the wrong sequence
Third-party security or filter drivers (antivirus, VPN) are intercepting system calls too early
Incompatible hardware was added and its driver is conflicting with an existing boot driver

How to Fix It

Boot into Safe Mode to bypass the problematic driver. Restart your PC and press F8 during startup (or hold Shift while clicking Restart in Windows). Choose 'Safe Mode.' Safe Mode loads only essential drivers, which usually avoids this BSOD and lets you troubleshoot.

If your PC boots fine in Safe Mode but crashes in normal mode, a third-party driver is the cause. Safe Mode is your diagnostic starting point.
Uninstall recently added hardware drivers. In Safe Mode, open Control Panel > Programs > Programs and Features. Sort by installation date. Uninstall any hardware drivers you added shortly before the crashes began. Also open Device Manager and remove any recently added devices.

New hardware drivers are the most common trigger for this error. If a new printer, network adapter, external device, or graphics card was recently installed, its driver is the prime suspect.
Use System Restore to roll back to before the problem started. In Safe Mode, type 'Create a restore point' in the Start menu and open it. Click 'System Restore.' Choose a restore point dated before the crashes began and follow the wizard.

System Restore does not affect your personal files. It reverses driver and system file changes. This is the fastest fix if a driver or software update caused the crash.
Repair the Windows boot environment using Startup Repair. Boot from a Windows USB drive (or the recovery partition). Choose 'Repair your computer' > 'Troubleshoot' > 'Advanced options' > 'Startup Repair.' Let it scan and fix boot issues automatically.

Corrupted boot files can cause drivers to load in the wrong order. Startup Repair specifically targets this type of problem.
Run the System File Checker from the recovery environment. On the same repair screen, choose 'Command Prompt' and type: sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows — then press Enter. This repairs system files even when Windows cannot start normally.

Replace C:\ with the actual Windows drive letter if needed. You can find it by typing: dir C:\ and checking if you see the Windows folder.

When to Call a Professional

If you cannot boot into Windows even in Safe Mode and all recovery tools fail, a technician can access your drive externally to repair the boot environment. Professionals can also replace boot files manually using Windows PE environments that do not rely on the damaged installation.

Frequently Asked Questions

My PC just shows a blue screen and restarts in a loop. How do I get in?

When Windows crashes three times in a row during startup, it automatically enters the Windows Recovery Environment (WinRE). From there, choose Troubleshoot > Advanced Options to access Safe Mode, Startup Repair, and System Restore. If WinRE does not appear, boot from a Windows USB installation drive and choose 'Repair your computer' instead of 'Install now.'

This started after I installed a new graphics card. Is that the cause?

Very likely, yes. New graphics cards require specific driver packages that include display drivers, audio components, and sometimes filter drivers. These can conflict with existing drivers if the old GPU drivers were not fully removed first. Boot into Safe Mode, use DDU (Display Driver Uninstaller, free tool) to completely remove all GPU drivers, then reinstall fresh drivers for your new card.

Will reinstalling Windows fix this?

Yes — a clean Windows reinstall will fix this error. But try the simpler fixes first: Safe Mode, System Restore, and Startup Repair. If you must reinstall, use the 'Reset this PC > Remove everything' option in Windows Recovery, or do a clean install from a USB drive. Back up your files before reinstalling — a full reset removes everything.