Computer error messages are designed by engineers, for engineers. They're often confusing, scary-looking, and unhelpful. This guide translates common Windows errors into plain English and tells you what to do about them.
Blue Screen of Death (BSOD)
The infamous "Blue Screen of Death" means Windows encountered a problem so serious it had to stop completely. Here's what a modern one looks like:
:(
Your PC ran into a problem and needs to restart.
We're just collecting some error info, and then we'll restart for you.
42% complete
Stop code: KERNEL_DATA_INPAGE_ERROR
What failed: ntfs.sys
What failed: ntfs.sys
The stop code at the bottom is the key to understanding what went wrong. Here are the most common ones:
KERNEL_DATA_INPAGE_ERROR
Critical
Stop code: KERNEL_DATA_INPAGE_ERROR
In Plain English:
Windows tried to read data from your hard drive or SSD, but the data wasn't there or was corrupted.
Common Causes
- Failing hard drive or SSD
- Faulty RAM (memory)
- Corrupted system files
- Loose SATA cable connection
What To Do:
Back up your important files immediately. This error often indicates hardware failure. Run a disk check (chkdsk) and memory test. If it recurs, professional diagnosis is recommended.
CRITICAL_PROCESS_DIED
Critical
Stop code: CRITICAL_PROCESS_DIED
In Plain English:
An essential Windows process (a program Windows needs to run) crashed or was terminated unexpectedly.
Common Causes
- Corrupted system files
- Bad Windows update
- Driver conflicts
- Malware infection
What To Do:
Try booting into Safe Mode (hold Shift while clicking Restart). Run System File Checker: open Command Prompt as admin and type sfc /scannow. If it happened after an update, try uninstalling recent updates.
DRIVER_IRQL_NOT_LESS_OR_EQUAL
Critical
Stop code: DRIVER_IRQL_NOT_LESS_OR_EQUAL
What failed: nvlddmkm.sys
What failed: nvlddmkm.sys
In Plain English:
A driver (software that controls hardware) tried to access memory it wasn't allowed to touch. The "What failed" line tells you which driver caused the problem.
Common Culprits
- nvlddmkm.sys - NVIDIA graphics driver
- atikmdag.sys - AMD graphics driver
- ntfs.sys - File system driver
- tcpip.sys - Network driver
What To Do:
Update or reinstall the driver mentioned in "What failed". For graphics drivers, download the latest version from NVIDIA or AMD's website. If you can't boot, try Safe Mode and roll back the driver.
WHEA_UNCORRECTABLE_ERROR
Critical
Stop code: WHEA_UNCORRECTABLE_ERROR
In Plain English:
WHEA stands for Windows Hardware Error Architecture. This means Windows detected a hardware problem that can't be automatically fixed.
Common Causes
- CPU overheating
- Failed overclocking settings
- Faulty RAM
- Power supply issues
- Failing motherboard
What To Do:
Check your CPU temperature (should be under 80°C under load). Reset BIOS to default settings. Test RAM with Windows Memory Diagnostic. This error usually requires professional hardware diagnosis.
Application Errors
Program.exe has stopped working
Warning
"Program.exe has stopped working. Windows is checking for a solution..."
In Plain English:
The program crashed. It tried to do something it couldn't handle and Windows had to close it forcibly.
Common Causes
- Bug in the program itself
- Conflicting software
- Corrupted program files
- Insufficient memory
What To Do:
Try restarting the program. If it keeps happening, try reinstalling the program. Check if there's an update available. Running as Administrator sometimes helps.
DLL File Missing
Warning
"The program can't start because MSVCP140.dll is missing from your computer."
In Plain English:
DLL files are shared code libraries that programs need to run. The program is looking for a file that should be there but isn't.
Common Missing DLLs
- MSVCP###.dll / VCRUNTIME###.dll - Visual C++ Runtime (install from Microsoft)
- d3dx9_##.dll - DirectX (common for games)
- XINPUT1_3.dll - Xbox controller support
What To Do:
Never download DLL files from random websites - they often contain malware. Instead, install the Microsoft Visual C++ Redistributable package or reinstall the program that's showing the error.
Access Denied
Info
"Access is denied" or "You need permission to perform this action"
In Plain English:
You're trying to do something that requires administrator privileges, or the file/folder is protected.
Common Situations
- Modifying files in Program Files or Windows folders
- Installing software
- Changing system settings
- Files owned by another user account
What To Do:
Right-click the program and select "Run as administrator". If it's a file you own, you might need to take ownership of it through the file's Properties → Security tab.
Disk & Storage Errors
Low Disk Space
Warning
"You are running low on disk space on Local Disk (C:)"
In Plain English:
Your main drive is almost full. Windows needs free space to work properly (for updates, temporary files, virtual memory).
Why It Matters
- Updates can't install
- Programs may crash
- Computer becomes very slow
- Some features stop working
What To Do:
Run Disk Cleanup (search in Start menu). Empty the Recycle Bin. Uninstall programs you don't use. Move large files (videos, photos) to an external drive. Aim for at least 10-20GB free.
Windows detected a hard disk problem
Critical
"Windows detected a hard disk problem. Back up your files immediately."
In Plain English:
Your hard drive is reporting errors to Windows. It might be starting to fail.
Warning Signs Before This
- Clicking or grinding noises
- Very slow file access
- Files disappearing or becoming corrupted
- Frequent freezing
What To Do:
Back up your important files immediately to an external drive or cloud storage. This is not a warning to ignore. Contact a professional for drive replacement before it fails completely.
Network & Internet Errors
DNS Server Not Responding
Warning
"DNS server not responding" or "DNS_PROBE_FINISHED_NXDOMAIN"
In Plain English:
DNS is like the phone book of the internet - it translates website names (google.com) into IP addresses. Your computer can't reach this "phone book".
Common Causes
- Router needs restart
- ISP having issues
- Wrong DNS settings
- Antivirus blocking DNS
What To Do:
Restart your router. Try using Google's DNS (8.8.8.8) or Cloudflare's (1.1.1.1) in your network settings. Temporarily disable your antivirus to test. If only one device is affected, restart that device.
Limited or No Connectivity
Warning
"Limited connectivity" or "No Internet Access" (yellow triangle on network icon)
In Plain English:
Your computer is connected to the router, but the router isn't connected to the internet (or your computer isn't getting a proper network address).
Common Causes
- Router/modem not connected to internet
- DHCP not working (not getting an IP address)
- IP address conflict
- ISP outage
What To Do:
Restart your router and modem (unplug for 60 seconds). Check if other devices can connect. Run Windows Network Troubleshooter (right-click network icon → Troubleshoot). Try releasing and renewing your IP address.
Quick Reference: Common Stop Codes
| Stop Code | Plain English | Likely Cause |
|---|---|---|
| MEMORY_MANAGEMENT | Memory problem detected | Faulty RAM |
| NTFS_FILE_SYSTEM | File system error | Disk corruption |
| SYSTEM_SERVICE_EXCEPTION | System service crashed | Driver or software conflict |
| PAGE_FAULT_IN_NONPAGED_AREA | Memory access error | RAM or driver issue |
| INACCESSIBLE_BOOT_DEVICE | Can't find boot drive | Disk problem or BIOS setting |
| BAD_POOL_HEADER | Memory pool corruption | Driver or RAM issue |
| VIDEO_TDR_FAILURE | Graphics driver crashed | GPU driver or overheating |
| KMODE_EXCEPTION_NOT_HANDLED | Kernel error | Driver incompatibility |
How to Capture Error Information
When you see an error, write down or photograph:
- The exact error message - word for word
- Stop code - the text after "Stop code:"
- What failed - the .sys or .dll file mentioned
- What you were doing when it happened
- When it started - after an update? New program?
This information helps us diagnose the problem much faster!
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Get Help NowFrequently Asked Questions
Are blue screens always serious?
A single blue screen can happen occasionally and isn't necessarily serious - it might be a one-time driver glitch. However, if you're getting them frequently (more than once a month), that indicates a real problem that should be investigated.
Should I download DLL files from the internet?
No! DLL download sites are notorious for distributing malware. The proper fix is to reinstall the program that's missing the DLL, or install the appropriate Microsoft Visual C++ Redistributable package from Microsoft's official website.
What does "Your PC ran into a problem" mean?
This is Windows 10/11's friendlier way of showing a blue screen error. It means something crashed badly enough that Windows couldn't recover and had to restart. The important information is the "Stop code" shown at the bottom of the screen.