When Windows 11 experiences a “Blue Screen of Death” (BSOD) or a sudden application crash, the operating system rarely provides a clear, human-readable explanation of what went wrong. Most users immediately open the Task Manager, but that only shows what is happening right now, not what happened five minutes ago. To diagnose past crashes and system instability, you need to use a hidden, built-in tool: Reliability Monitor.
The Reliability Monitor acts as a flight data recorder for your PC, tracking software installations, application failures, and hardware errors over time. In this guide, you will learn how to access and interpret the Reliability Monitor to fix your PC.
How to Access the Reliability Monitor
Because Microsoft has buried this tool deep within the legacy Control Panel, searching for it requires a specific phrase:
- Click the Start button or press the Windows key.
- Type View reliability history into the search bar.
- Press Enter or click the corresponding Control Panel result.
The Reliability Monitor window will open, displaying a graph spanning the last few days or weeks.
Understanding the Reliability Graph
The core of the interface is the Stability Index graph, which scores your system’s health on a scale from 1 (terrible) to 10 (perfect). Every time your computer crashes, the blue line drops. When your computer runs smoothly, the line climbs back up.
Beneath the graph, you will see columns representing specific days. Look for days marked with icons:
- Red ‘X’ Circle: Represents a critical event, such as a Blue Screen of Death, an unexpected shutdown, or an application completely freezing and crashing.
- Yellow Warning Triangle: Represents a non-critical error, usually a failed background software update or a driver installation failure.
- Blue ‘i’ Circle: Represents informational events, such as successful software installations or routine Windows Updates.
Diagnosing a Crash
To find out exactly why your computer crashed on a specific day:
- Click on the column for the day the crash occurred.
- The bottom half of the window will populate with a list of specific events that happened on that day, categorised by “Application failures”, “Windows failures”, and “Miscellaneous failures”.
- Look for a critical event marked with a red ‘X’. For example, you might see “Microsoft Word – Stopped working” or “Windows – Stopped responding and was closed”.
- Double-click the specific event, or click View technical details next to it.
Interpreting the Technical Details
The technical details window provides the raw data you need to fix the problem. You are looking for two specific pieces of information:
1. Faulting Application Name
This tells you exactly which piece of software triggered the crash. If you see chrome.exe constantly failing, you know you need to reinstall Google Chrome or disable a faulty browser extension.
2. Faulting Module Name
This is often the most important clue. The “module” is the specific file (usually a .dll or .sys file) that caused the application to crash.
- If the faulting module is
nvlddmkm.sys, a quick Google search will reveal that this is the NVIDIA graphics driver. The solution is to update or reinstall your graphics card drivers. - If the faulting module is
ntdll.dll, it indicates a deep Windows core issue, suggesting you might need to run a System File Checker (SFC) scan.
Checking for Solutions Automatically
Windows attempts to crowdsource solutions for common crashes. At the bottom of the Reliability Monitor, you can click Check for solutions to all problems. Windows will cross-reference your crash logs with Microsoft’s database and, if a known patch exists, it will prompt you to download it.
By learning to read the Reliability Monitor, you stop guessing why your computer is crashing and start applying precise, targeted fixes.