Common Scenario
PC crashes to blue screen (BSOD) with error codes like "IRQL_NOT_LESS_OR_EQUAL", "CRITICAL_PROCESS_DIED", or "SYSTEM_THREAD_EXCEPTION_NOT_HANDLED"
Step-by-Step Troubleshooting
-
Identify
- Note exact error code/message (take photo with phone if possible)
- When does it happen?
- During startup?
- After specific app opens?
- Randomly during normal use?
- How often? (once, multiple times, constantly?)
- Recent changes? (new software, Windows update, driver update?)
-
Theory
- Driver issue (most common - 60-70% of BSODs)
- RAM problem (bad memory module)
- Overheating (especially laptops)
- Windows system file corruption
- Recent Windows update compatibility issue
-
Test
Boot into Safe Mode (isolates driver/software issues):
- Method 1: Hold Shift while clicking Restart
- Choose: Troubleshoot → Advanced → Startup Settings → Restart
- Press 4 or F4 for Safe Mode
- If PC works fine in Safe Mode → driver/software issue confirmed
Check Event Viewer for clues:
- Win + X → Event Viewer
- Windows Logs → System
- Look for red Error entries around crash time
- Note which driver/service is mentioned
-
Implement
A) Update all drivers:
- Device Manager (Win + X)
- Expand each category (Display adapters, Network adapters, etc.)
- Right-click each device → Update driver
- Focus on: Graphics card, Network adapter, Chipset
B) Run System File Checker:
- Open Command Prompt as admin
- Type:
sfc /scannow - Wait 15-30 minutes
- Restart if it finds/fixes issues
C) Check RAM:
- Win + S → Search "Windows Memory Diagnostic"
- Choose "Restart now and check"
- PC restarts and tests memory (takes 10-20 mins)
- Check results after restart in Event Viewer
D) Uninstall recent software:
- Settings → Apps → Apps & features
- Sort by install date
- Uninstall anything added in past week
E) Roll back Windows Update (if recent):
- Settings → Update & Security → Windows Update → View update history
- Uninstall updates (if crash started after specific update)
-
Verify
- PC runs normally for 24-48 hours without crash
- Monitor for any error patterns
- Check temps if overheating suspected (free tools: HWMonitor, Core Temp)
-
Document
- Exact BSOD error code
- Event Viewer entries
- Drivers updated
- Memory test results
- Resolution steps
Screenshots:
-bsod-example
-event-viewer-critical
-device-manager-update
Common Essex Home/Office Patterns
- Graphics driver BSODs common after Windows updates
- Network adapter drivers on Dell/HP laptops often cause crashes
- Overheating BSODs in summer (poor ventilation in home offices)
Escalation
If BSOD persists after:
- All driver updates
- SFC scan clean
- Memory test passed
- Safe Mode also crashes → Escalate to 2nd line for:
- Advanced diagnostics (dump file analysis)
- Possible hardware failure (motherboard, PSU)
- OS reinstall consideration
Typical Resolution Time: 20–60 minutes (driver update), 2+ hours (deep troubleshooting) Lessons Learned
From CompTIA A+ hardware module and Google IT OS module. Most BSODs are driver-related and resolved by updates. RAM issues less common but require hardware replacement.