Why Is My Computer So Slow? 12 Fixes for Windows and Mac

A slow computer is one of the most frustrating tech problems, but the fix is often simpler than you think. Whether your laptop takes minutes to boot, programs freeze constantly, or everything just feels sluggish, these 12 solutions will speed up your Windows PC or Mac in 2026.

1. Restart Your Computer

This sounds basic, but restarting clears temporary files, resets memory (RAM), and closes background processes that accumulate over time.

• Windows: Start → Power → Restart (not Shut Down, which uses Fast Startup and doesn’t fully reset)
• Mac: Apple menu → Restart

If you haven’t restarted in days or weeks, this alone can dramatically improve speed.

2. Check What’s Using Your Resources

Find which programs are consuming CPU, RAM, or disk:

Windows:

1. Press Ctrl + Shift + Esc to open Task Manager
2. Click the CPU, Memory, or Disk column to sort by usage
3. Right-click any process using excessive resources → "End task"

Mac:

1. Open Activity Monitor (Spotlight → search "Activity Monitor")
2. Click the CPU or Memory tab
3. Sort by usage to find resource-heavy processes
4. Select the process → click the X button to quit it

Common culprits: web browsers with too many tabs, antivirus scans, cloud sync apps (OneDrive, Dropbox, Google Drive), and Windows Update.

3. Close Unnecessary Browser Tabs

Each browser tab uses 50–300MB of RAM. If you have 20+ tabs open, that’s potentially 4–6GB of memory consumed by your browser alone.

• Close tabs you’re not actively using
• Use a tab manager extension like OneTab or The Great Suspender to hibernate inactive tabs
• Chrome users: type chrome://memory-internals in the address bar to see per-tab memory usage

4. Disable Startup Programs

Too many programs launching at boot slow down startup significantly:

Windows:

1. Open Task Manager (Ctrl + Shift + Esc)
2. Click the "Startup apps" tab
3. Right-click programs you don’t need at startup → "Disable"
4. Keep essentials (antivirus, audio drivers) but disable things like Spotify, Discord, Steam, Adobe updaters

Mac:

1. Go to System Settings → General → Login Items
2. Remove apps you don’t need at startup by selecting them and clicking the minus (−) button
3. Also check "Allow in the Background" and disable unnecessary background items

5. Free Up Disk Space

A nearly full hard drive significantly slows performance. Your computer needs 10–20% free space for virtual memory, temp files, and system operations.

Windows:

1. Open Settings → System → Storage
2. Click "Temporary files" and delete them
3. Enable Storage Sense to automatically clean up old files
4. Run Disk Cleanup: search "Disk Cleanup" in Start, select your drive, check all boxes

Mac:

1. Click Apple menu → About This Mac → Storage (or System Settings → General → Storage)
2. Click "Manage" and review recommendations
3. Empty the Trash (it doesn’t actually free space until emptied)
4. Delete old Downloads, unused applications, and large files

6. Check for Malware

Malware running in the background can consume resources and slow your computer dramatically:

Windows:

1. Open Windows Security (search in Start menu)
2. Click "Virus & threat protection" → "Quick scan"
3. Run a "Full scan" for a deeper check
4. Consider running Malwarebytes (free version) for a second opinion

Mac:

• macOS includes built-in malware protection (XProtect), but consider running Malwarebytes for Mac if you suspect infection
• Check Activity Monitor for unfamiliar processes using high CPU

7. Update Your Operating System and Drivers

Updates often include performance fixes and optimizations:

Windows:

1. Go to Settings → Windows Update
2. Click "Check for updates" and install any available
3. Also update GPU drivers from NVIDIA GeForce Experience, AMD Radeon Software, or Intel Arc Control

Mac:

1. Go to System Settings → General → Software Update
2. Install any available macOS updates

8. Upgrade to an SSD

If your computer still uses a traditional hard drive (HDD), upgrading to an SSD is the single biggest speed improvement you can make. Boot times drop from 2–3 minutes to under 15 seconds, and everything feels dramatically snappier.

• Most laptops from 2018+ already have SSDs — check by opening Task Manager (Windows) → Performance → Disk, or About This Mac (Mac) → Storage
• 500GB SSDs cost under $40 in 2026, and 1TB under $70
• Clone your existing drive to the new SSD using free tools like Macrium Reflect (Windows) or Carbon Copy Cloner (Mac)

9. Add More RAM

If your computer has 4GB or 8GB of RAM and you regularly use multiple apps:

• 8GB is the minimum for comfortable use in 2026
• 16GB is recommended for multitasking
• 32GB for video editing, large datasets, or running virtual machines

Check current RAM: Task Manager → Performance → Memory (Windows) or About This Mac (Mac).

Note: Many modern laptops (MacBooks, ultrabooks) have soldered RAM that can’t be upgraded. Check before purchasing.

10. Disable Visual Effects

Animations and transparency effects use GPU and CPU resources:

Windows:

1. Search for "Adjust the appearance and performance of Windows" in Start
2. Select "Adjust for best performance" to disable all effects
3. Or selectively keep "Smooth edges of screen fonts" and "Show thumbnails instead of icons"

Mac:

1. Go to System Settings → Accessibility → Display
2. Enable "Reduce motion" and "Reduce transparency"

11. Run a Disk Check

Corrupted files or drive errors can cause slowdowns:

Windows:

1. Open Command Prompt as Administrator
2. Type chkdsk C: /f /r and press Enter
3. If prompted, type Y to schedule on next restart
4. Restart your computer to let the scan run

Mac:

1. Restart and hold Cmd + R to enter Recovery Mode
2. Open Disk Utility
3. Select your drive → click "First Aid" → "Run"

12. Reset or Reinstall Your OS (Last Resort)

If nothing else works, a fresh start can restore original performance:

Windows:

1. Go to Settings → System → Recovery
2. Click "Reset this PC"
3. Choose "Keep my files" (reinstalls Windows while preserving personal files) or "Remove everything" for a clean slate

Mac:

1. Back up with Time Machine first
2. Restart and hold Cmd + R for Recovery Mode
3. Select "Reinstall macOS"

Performance solutions tested on Windows 11 24H2 and macOS Sequoia 15.3 across Dell, HP, Lenovo, ASUS, MacBook Air M3, and MacBook Pro M3 Pro. Last updated March 2026 by the DevX editorial team — our hardware and performance specialists have helped speed up thousands of computers over 15+ years.

More Troubleshooting Guides From DevX

• My Computer Won’t Turn On
• Why Is My Phone So Slow
• How To Free Up Space on Android
• How To Get More Storage on iPhone
• How To Clear Cache in Chrome

Editorial Staff