# Blue Screen: CRITICAL_PROCESS_DIED (Stop code 0x000000EF)

**Code:** `CRITICAL_PROCESS_DIED` · **Category:** Windows · **Seen on:** Windows

A process Windows can’t run without (csrss, wininit, smss…) stopped unexpectedly, so the system halted.

## Meaning

Usually caused by corrupted system files, failing storage, bad drivers or an interrupted update. If it happens at every boot, use Windows Recovery (WinRE) to repair.

## Common causes

- Corrupted system files after a failed update
- Failing SSD/HDD (bad sectors)
- Faulty driver
- Malware tampering with system processes

## Quick fix

1. Run `sfc /scannow` and DISM RestoreHealth
2. Check the disk: `chkdsk C: /f /r` and the drive’s SMART status
3. Uninstall the latest update from WinRE if it started afterwards
4. Use System Restore

## Detailed fix by platform

### Windows

1. From WinRE Command Prompt (offline repair):

```bat
sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows
chkdsk C: /f /r
```


## How to diagnose

1. **Trigger** — After an update, driver install or randomly?
2. **Disk health** — SMART status / chkdsk results
3. **System files** — SFC/DISM results

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Source: [WhatIsMyError](https://whatismyerror.com/errors/windows/critical-process-died)