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.
Get Professional PC RepairStep 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Outdated drivers, especially graphics and storage drivers, can cause performance issues.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
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)
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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