PC Performance

How to Fix a Slow Windows 11 Computer

A slow computer is the most common IT complaint from both home users and businesses. Before buying new hardware, work through these steps. Most slow PCs can be fixed in under 30 minutes with software changes.

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100%disk usage is the top cause

30 minto diagnose most issues

Step 1: Check What Is Using Resources Right Now

Open Task Manager (press Ctrl + Shift + Esc) and click the Processes tab. This tells you exactly what is slowing your PC down.

Sort by CPU

If any process is consistently above 30%, that is your bottleneck

Sort by Memory

If total usage is above 90%, you need more RAM or fewer programs

Sort by Disk

If disk usage is stuck at 100%, that is the most common cause of slowness

Pro tip: If Task Manager shows 100% disk usage on a spinning hard drive (HDD), upgrading to an SSD is the single most impactful hardware change you can make. It typically makes a PC feel 5-10x faster.

Step 2: Disable Startup Programs

Too many programs launching at startup is the most common cause of slow boot times and overall sluggishness. Open Task Manager > Startup apps, sort by Startup impact, and disable anything you do not need immediately at login.

Program	Safe to Disable?
Microsoft Teams	Yes - it opens when you click it
Spotify	Yes
Adobe Creative Cloud	Yes - starts when you open an Adobe app
OneDrive	No - leave enabled if you use file sync
Antivirus	No - leave enabled
Printer software / bloatware	Yes
Game launchers (Steam, Epic)	Yes

Step 3: Check for Malware

Malware is a common cause of unexpected slowness, especially if the PC is running cryptocurrency miners or adware in the background.

Run a Full Windows Defender Scan

Open Windows Security > Virus & threat protection
Click Scan options > Full scan
Click Scan now and let it complete

Check for Suspicious Processes

Open Task Manager
Look for processes you do not recognise
Right-click > Search online to check what they are

Step 4: Free Up Disk Space

Windows 11 needs at least 20GB of free space on the system drive to function properly. When space runs low, performance degrades significantly.

Use Disk Cleanup

Search for Disk Cleanup in Start
Select all categories including Windows Update Cleanup
Include Previous Windows installations if available

Enable Storage Sense

Open Settings > System > Storage
Turn on Storage Sense
Configure it to run automatically

Step 5: Update Windows and Drivers

Outdated drivers, especially graphics and storage drivers, can cause performance issues.

Open Settings > Windows Update > Check for updates
Install all pending updates
Click Advanced options > Optional updates to check for driver updates

Step 6: Check Disk Health

A failing hard drive will cause random freezes and extreme slowness. Check your disk health to rule this out.

Open PowerShell as Administrator
Run: Get-PhysicalDisk | Select-Object FriendlyName, MediaType, HealthStatus
Run a file system check: chkdsk C: /f /r

Important: If the health status reports anything other than "Healthy", back up your data immediately. A failing drive can stop working at any time without further warning.

Step 7: Adjust Visual Effects

Windows 11's animations and transparency effects consume resources on older hardware. Disabling them can noticeably improve performance.

Press Win + R, type sysdm.cpl, press Enter
Go to Advanced tab > Performance > Settings
Select Adjust for best performance (disables all visual effects)
Optionally re-enable Smooth edges of screen fonts for readability

Step 8: Check RAM Usage

If your PC has 4GB or less of RAM and you regularly use a web browser with multiple tabs, you will experience constant slowness.

Usage	Minimum RAM	Recommended
Basic office work (email, documents)	4 GB	8 GB
Web browsing with 10+ tabs	8 GB	16 GB
Video editing, development, VMs	16 GB	32 GB

To check your installed RAM, open Task Manager > Performance tab > Memory. The total amount is shown in the top-right corner.

Step 9: Reset Windows (Last Resort)

If nothing else works, a Windows reset reinstalls the OS while optionally keeping your files. This is the nuclear option but often the most effective fix for heavily degraded systems.

Open Settings > System > Recovery
Click Reset this PC
Choose Keep my files (reinstalls Windows but preserves documents) or Remove everything (clean start)

For business PCs, a reset should be coordinated with your IT team to ensure the device re-enrols in Intune and receives the correct policies after reset.

Quick Diagnosis Reference

Symptom	Most Likely Cause	Fix
100% disk usage	HDD bottleneck or Windows Search indexing	Upgrade to SSD or disable Indexing
Slow boot (2+ minutes)	Too many startup programs	Disable unnecessary startup apps
High memory usage	Not enough RAM or memory leak	Close tabs/apps, upgrade RAM
Random freezes	Failing drive or overheating	Check disk health, clean dust
Slow after Windows Update	Update installing in background	Wait for completion, then restart
Everything slow, always	4GB RAM with HDD	Upgrade to SSD and 8GB+ RAM

Still Struggling with a Slow PC?

If you have tried these steps and your computer is still slow, there may be a deeper hardware or software issue at play. Our technicians can diagnose the problem remotely and get your PC running like new again.

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