Key Objectives
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3.1 Troubleshooting Methodology
Apply the CompTIA troubleshooting model to software and OS problems
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3.2 Windows OS Issues
Resolve boot failures, BSoD, slow performance, and application crashes
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3.3 Application Problems
Fix application installation failures, compatibility issues, and crashes
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3.4 Security Symptoms
Identify and resolve malware infections, browser hijacks, and unauthorized access
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3.5 Mobile OS Issues
Troubleshoot iOS and Android problems including connectivity and app issues
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3.6 Recovery Options
Use Safe Mode, System Restore, recovery partitions, and reset options
CompTIA Troubleshooting Methodology
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1
Identify the Problem
Gather information, question users, identify symptoms, determine recent changes
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2
Establish a Theory
Consider multiple causes, start with obvious/simple causes, research if needed
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3
Test the Theory
Confirm theory by testing. If not confirmed, establish new theory
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4
Establish a Plan of Action
Create plan to resolve the problem, consider impact, get approval if needed
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5
Implement the Solution
Execute the plan, escalate if necessary, make changes as needed
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6
Verify Functionality
Confirm the fix worked, implement preventive measures
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7
Document Findings
Record the problem, solution, and outcome for future reference
Common Troubleshooting Scenarios
Blue Screen of Death (BSoD)
System crashes with blue error screen
Check drivers, RAM, Windows updatesSlow Boot Time
System takes too long to start
Disable startup programs, check disk healthApplication Crashes
Programs freeze or close unexpectedly
Update app, check compatibility, reinstallMissing DLL Errors
Application can't find required files
Reinstall app, run SFC, check for malwareProfile Load Failure
User profile won't load at login
Create new profile, restore from backupBrowser Hijack
Unwanted homepage, redirects, pop-ups
Run anti-malware, reset browser settingsEssential Troubleshooting Commands
sfc /scannow
System File Checker
DISM
Repair Windows image
chkdsk
Check disk integrity
bootrec
Repair boot records
msconfig
Startup configuration
eventvwr
View system logs
Exam Tips for Domain 3
This domain is heavily scenario-based. Memorize the 7-step troubleshooting methodology - questions often ask "what should you do FIRST?" Know when to use Safe Mode vs. Safe Mode with Networking. Understand Windows recovery options: System Restore (settings), Reset This PC (reinstall), and Recovery Drive (boot problems).
