Adeleke Dare

Posted on Jul 5

🧰 Tech Support Series: Fixing a Slow Windows PC

#windows #troubleshooting #performance #itsupport

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:

Press Windows + R, type sysdm.cpl, and press Enter
Go to the Advanced tab and click on Settings under the Performance section
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!

Follow me for more practical IT guides and real-world troubleshooting logs.

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