🧰 Tech Support Series: Fixing a Slow Windows PC

Have you ever faced a situation where your PC just starts crawling, apps take forever to load, the system freezes at random, and everything feels painfully slow?

In this guide, I’m documenting the steps I practised in my personal IT lab to troubleshoot a slow Windows PC—something almost every support technician faces early in their journey.

Whether you're fixing your own device or preparing for helpdesk work, these steps reflect real-world IT support thinking.

🧠 Problem Summary

"My Windows PC has suddenly become very slow. It takes a long time to boot, apps hang, and even browsing the internet feels laggy."

Common complaint, right?

🔍 Possible Causes

Before jumping into solutions, it’s helpful to understand why a PC might slow down:

• Too many apps starting up with Windows
• Low RAM or storage space
• Malware or unknown background processes
• Disk fragmentation (for HDDs)
• Windows Updates running silently
• Poorly optimized system settings
• Hardware issues (wear or overheating)

🛠️ Step-by-Step Troubleshooting

Let’s walk through some reliable steps I tested in my lab.

✅ Step 1: Open Task Manager

Press Ctrl + Shift + Esc to open Task Manager.

• Check the Performance tab
• Observe which resources (CPU, Memory, Disk) are under heavy use
• Go to the Processes tab, sort by CPU or Memory to identify which apps are consuming the most resources.

🔍 Pro Tip: This helps identify if it's a memory issue, a background process hogging CPU, or something else.

✅ Step 2: Disable Unnecessary Startup Programs

Still in Task Manager, switch to the Startup tab and disable non-essential apps like:

• Adobe Updater
• Skype
• OneDrive (if not needed)
• And any other unnecessary apps.

Restart the PC and see if performance improves.

🚫 Remember: The fewer programs that auto-start, the faster the PC can boot and respond.

✅ Step 3: Run Disk Cleanup

Press Windows + R to open the windows run box, type cleanmgr, and press Enter.

• Select the system drive (usually C:)
• Tick checkboxes for:
  • Temporary files
  • Thumbnails
  • Recycle Bin
  • System-created error files

💡 Impact: This can recover gigabytes of space on old systems.

✅ Step 4: Uninstall Unused Programs

Go to Control Panel > Programs > Uninstall a program

Look out for:

• Old toolbars
• Trial software
• Anything you don’t recognise

🧹 A clean system is a faster system.

✅ Step 5: Scan for Malware

Use Windows Defender or install Malwarebytes.

• Perform a Full Scan (not just quick)
• Quarantine and remove any threats found
• Reboot and check for improvements

🛡️ Warning: Malware can silently eat up system resources in the background.

✅ Step 6: Check for Hardware Issues

Sometimes, hardware problems can cause a PC to slow down. Here are a few things to check:

• Hard Drive Health: Use tools like CrystalDiskInfo to check the health of your hard drive or SSD
• RAM: Ensure that your RAM is functioning properly. You can use the Windows Memory Diagnostic tool to check for memory issues
• Overheating: Make sure your PC is not overheating. Check the fans and clean any dust buildup

🛠 Preventing hardware failure starts with early detection.

✅ Step 7: Adjust Visual Effects for Better Performance

Windows uses various visual effects that can be adjusted for better performance. Here's how:

1. Press Windows + R, type sysdm.cpl, and press Enter
2. Go to the Advanced tab and click on Settings under the Performance section
3. Choose Adjust for best performance or customize the settings manually

🎨 You might lose a few animations, but gain real speed.

💻 Useful Commands for Troubleshooting

Here are some essential Windows commands that can help diagnose and fix performance issues:

System Information & Diagnostics

# Get detailed system information systeminfo # Check system file integrity sfc /scannow # Check and repair disk errors chkdsk C: /f /r # Windows Memory Diagnostic mdsched.exe # Check disk usage by directory # Note: This gives you a rough total, but it can take a long time on large drives. dir C:\ /s /-c | find "bytes" 

Performance Monitoring

# Monitor system performance in real-time perfmon.exe # Resource Monitor for detailed resource usage resmon.exe # Event Viewer to check system logs eventvwr.msc # Check running services services.msc 

Network & Process Management

# List all running processes with resource usage tasklist /v # Kill a specific process taskkill /f /pid [ProcessID] # Check network connections netstat -an # Flush DNS cache ipconfig /flushdns # Reset network settings netsh winsock reset 

Disk & Storage Management

# Check disk space usage dir C:\ /-c # Defragment hard drive (HDD only) defrag C: /a # Optimize SSD (TRIM command) defrag C: /L # Clean temporary files via command line cleanmgr /sagerun:1 

Advanced Troubleshooting

# Check Windows Update history wuauclt /detectnow # Reset Windows Update components net stop wuauserv net stop cryptSvc net stop bits net stop msiserver # Generate system health report perfmon /report # Check startup programs msconfig 

💡 Pro Tip: Run Command Prompt as Administrator for most of these commands to work properly. Right-click on Command Prompt and select "Run as administrator".

🧼 Prevention Tips

• Keep Windows and drivers up to date
• Don't install unknown apps or click suspicious links
• Run regular malware scans
• Restart your PC at least a few times a week
• Regularly clean up temporary files and unused programs
• Monitor your PC's performance and address issues as they arise

🧠 Prevention reduces future support calls (even to yourself!).

✅ Final Thoughts

This was a simulated support scenario in my personal IT lab, but these steps reflect real IT support practices. Slow system performance is a common issue—knowing how to troubleshoot it step-by-step helps build both technical and communication skills.

I'll be sharing more posts in this series as I build my skills toward a full DevOps/IT support path. Stay tuned for the next one!

What's your go-to method for fixing slow PCs? Share your experiences in the comments below!

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