Windows 11 Running Slow? 10 Proven Fixes That Work

If your Windows 11 PC has become slow, there's almost always a specific fixable cause — no need to reformat or buy new hardware. This guide covers everything from gradual slowdowns to sudden freezes.

Quick fix (TL;DR)

• Restart the PC to clear processes stuck in memory
• Open Task Manager (Ctrl+Shift+Esc) → sort by CPU/Memory → find the heavy process
• Startup tab → disable all non-essential startup apps
• Free up disk space on C: (keep at least 15 GB free)
• Update your GPU driver from the manufacturer's website

Causes

• Too many startup apps: every program launching with Windows occupies RAM from the first minute
• Full or nearly full disk: Windows uses free space as virtual memory — below 10% free means severe slowdowns
• Malware running in background: a crypto miner or spyware can silently consume 100% CPU
• Outdated or corrupt drivers: GPU, chipset, or SSD drivers cause hard-to-diagnose bottlenecks
• Windows Update running in background: the update service downloads, indexes, and installs without notification
• Insufficient RAM: with 4-8 GB and many apps open, Windows starts using the page file (10× slower than RAM)
• Mechanical HDD: an old spinning disk is the single biggest cause of a slow modern PC
• Visual effects and animations: transparency and animations consume GPU/CPU on older hardware

Step-by-step guide

Step 1 — Identify the offending process

1. Press Ctrl+Shift+Esc to open Task Manager
2. Click the CPU header to sort by highest consumption
3. If a process consistently uses >30% CPU, right-click → Open file location to identify it
4. Search the process name online: [process name] high CPU to determine if it's legitimate or malware
5. Repeat sorting by Memory to find memory leaks

Step 2 — Disable unnecessary startup programs

1. In Task Manager → Startup tab
2. Sort by Startup impact (High/Medium/Low)
3. Right-click each High-impact app you don't need immediately → Disable
4. Common candidates: Spotify, Discord, Teams, Skype, OneDrive (if not essential), game launchers
5. Changes take effect on the next restart

Step 3 — Free up disk space on C:

1. Search for Disk Cleanup in the Start menu → select C: drive → OK
2. Check: Temporary files, Thumbnails, Recycle Bin, Windows Update Cleanup
3. Click Clean up system files for additional options (includes previous Windows installation files)
4. Goal: at least 15-20 GB free on C:
5. Enable Storage Sense: Settings → System → Storage → toggle it on for automatic cleanup

Step 4 — Update Windows and drivers

1. Start → Settings → Windows Update → Check for updates
2. For GPU drivers (high priority): open Device Manager → Display adapters → right-click → Update driver
3. Better yet: download drivers directly from NVIDIA, AMD, or Intel
4. For audio, chipset, and network drivers: download from your motherboard or laptop manufacturer's website

Step 5 — Reduce visual effects

1. Search Adjust the appearance and performance of Windows in the Start menu
2. Select Adjust for best performance to remove all animations
3. Or keep only: Show thumbnails instead of icons and Smooth edges of screen fonts
4. Most effective on PCs with 4-8 GB RAM or integrated graphics

Step 6 — Scan for malware

1. Start → Windows Security → Virus & threat protection
2. Click Quick scan (2-3 minutes)
3. For a deeper scan: Scan options → Full scan
4. Also run Malwarebytes Free as a complementary scan — it catches spyware and adware that Defender may miss

Step 7 — Repair system files

Open Command Prompt as Administrator (right-click Start → Windows Terminal as administrator) and run these two commands in order:

sfc /scannow
DISM /Online /Cleanup-Image /RestoreHealth

The first checks and repairs corrupted system files. The second downloads repair files from Microsoft. Restart after completion.

Step 8 — Set power plan to High Performance

1. Search Power plan → Choose a power plan
2. Select High performance (or Ultimate Performance if available)
3. On laptops: accept faster battery drain as a trade-off
4. This eliminates CPU throttling imposed by the Balanced power plan

Common mistakes to avoid

• ❌ Using third-party optimizers (CCleaner, Advanced SystemCare, etc.): they remove harmless files and often bundle adware
• ❌ Killing system processes (svchost.exe, dwm.exe, lsass.exe): causes instability or blue screens
• ❌ Disabling Windows Defender to "speed things up": real-world impact is minimal on modern hardware; disabling it exposes you to malware
• ❌ Ignoring a full disk: one of the most common causes of sudden slowdowns, and the easiest to fix
• ❌ Expecting software-only miracles: with 4 GB RAM and an old HDD, software optimizations have physical limits

When the bottleneck is hardware

If you've done all of the above and the PC is still slow, the problem is hardware:

• Upgrade to 16 GB RAM: the cheapest and most impactful upgrade for PCs running 8 GB or less
• Replace HDD with SSD: turns a painfully slow PC into a snappy one in 30 minutes — night and day difference
• Clean reinstall Windows 11: a fresh installation resolves deep corruption and bloat accumulated over years

For boot-specific slowness, also see Windows 11 slow boot fix and how to free up disk space on Windows 11.