Windows 11 Slow Performance: Causes and Fixes That Work

Windows 11 slow performance has a handful of usual suspects: too many apps launching at startup, a drive that is almost full, a power plan tuned for battery life, background work you cannot see, and sometimes hardware that is simply at the edge of what Windows 11 needs. Rather than applying every tweak you can find, it pays to measure first, fix the actual bottleneck, and leave the rest alone.

These steps apply to Windows 11 version 24H2 and 25H2 on Home and Pro. If the slowdown started right after an update, also see our slow after update fixes.

Step 1: Find the bottleneck in Task Manager

Press Ctrl + Shift + Esc to open Task Manager.

• On the Processes page, select the CPU, Memory and Disk column headers to sort by each. Anything consistently near the top while you are not using it deserves a closer look.
• On the Performance page, check which resource is running near 100%. Memory near full means Windows is paging to disk; disk at 100% with low transfer speeds often means a slow hard drive.

What Task Manager shows	Likely cause	Where to go
CPU high with one app on top	A busy or stuck app	Close or update that app
Memory near full	Too many apps, or too little RAM	Startup apps, see hardware section
Disk at 100%	Hard disk drive, indexing, updates	Disk usage 100%
Everything low but still sluggish	Power mode, visual effects, drivers	Steps 4 and 5

Background work right after a fresh install or big update, such as indexing and Windows Update, is normal and settles down after a while. Leave the PC on and plugged in for an hour or so before judging it.

Step 2: Restart and install updates

A restart clears memory leaks and finishes pending update work. Then open Settings > Windows Update, select Check for updates, install everything offered and restart again. Updates often include driver and performance fixes. Also check Advanced options > Optional updates for driver updates if you suspect a specific device.

Step 3: Cut down startup apps

Every app that starts at sign-in uses memory and CPU time, and many do not need to.

1. Open Settings > Apps > Startup.
2. Sort by Startup impact.
3. Turn off apps you do not need running all the time, such as game launchers, chat apps you rarely use and updaters.

You can do the same on the Startup apps page of Task Manager. Keep security software and anything for hardware you rely on, like touchpad or audio utilities. Our startup apps guide explains what is usually safe to disable.

Step 4: Free up disk space with Storage Sense

A system drive that is nearly full slows updates, paging and app installs.

1. Open Settings > System > Storage.
2. Turn on Storage Sense so Windows automatically clears temporary files and, if you choose, the Recycle Bin and old downloads.
3. Select Cleanup recommendations to review large or unused files, temporary files and apps you no longer use.

If you use OneDrive, Storage Sense can also make files you have not opened recently online-only, freeing space while keeping them in the cloud.

Step 5: Change power mode and visual effects

Power mode controls how hard Windows lets the processor work.

1. Open Settings > System > Power & battery (on desktops without a battery, Settings > System > Power).
2. Under Power mode, choose Best performance.

Laptops have separate settings for when they are plugged in and on battery on some models. Best performance uses more power and may make the fans run more.

Visual effects such as animations and shadows look nice but cost a little performance on older hardware. Search for “Adjust the appearance and performance of Windows”, open it, and choose Adjust for best performance, or untick individual effects. Turning these off also makes the interface feel snappier on low-end machines. You can also turn off Animation effects and Transparency effects in Settings > Accessibility > Visual effects.

Step 6: Scan for malware

Malware can eat CPU, disk and network in the background. Open Windows Security > Virus & threat protection and run a Quick scan. If anything is found, or if you are still suspicious, select Scan options and run a Full scan or a Microsoft Defender Offline scan, which restarts the PC and scans before Windows loads. See our Microsoft Defender guide for more.

Step 7: Repair system files

If Windows feels sluggish and also shows errors or crashes, damaged system files could be involved. Running System File Checker from an administrator Command Prompt checks and repairs them. Our sfc /scannow guide walks through it.

Step 8: Know your hardware limits

Some PCs are slow because of their hardware, and no setting will change that.

• Hard disk drive (HDD): Windows 11 on a spinning hard drive is noticeably slow to start, update and open apps. Task Manager’s Performance page shows the drive type as HDD or SSD. Moving to an SSD is the single biggest upgrade most older PCs can get.
• 4 GB of RAM: this is the Windows 11 minimum, and a modern browser with several tabs can use most of it on its own. If memory sits near full in Task Manager, adding RAM helps more than any tweak. Check whether your model can be upgraded; many thin laptops have memory soldered to the board.
• Older processors and thermal limits: dust-clogged fans cause processors to slow down to protect themselves. Cleaning vents can restore speed on older laptops.

Avoid registry cleaners, “debloat” scripts and memory optimiser apps. They are not needed and can cause new problems. If nothing helps and Windows itself seems damaged, Reset this PC with Keep my files gives you a clean system without losing personal files.