---
title: Slow PC
category: Windows
summary: A computer that is slow to start, slow to open programs, or freezes during normal work.
applies_to: Windows 10 / Windows 11
related: 09-disk-space-low, 10-malware-cleanup-basics, 03-wifi-not-connecting
---

## Symptoms

- Long start-up or sign-in time.
- Programs take a long time to open, or the mouse lags.
- Fan constantly loud, or the laptop gets very hot.
- "Not responding" windows, or the disk light stays on.

## Before you start

- Is it slow all the time, or only in one program or website? One program points to that program; everything points to the PC.
- When did it start? After an update, a new install, or gradually?
- How old is the PC, and does it have an SSD or a traditional hard drive?

## Steps

1. **Restart it.** A restart (not just closing the lid) clears many temporary problems. Note how long it has been since the last restart.
2. **Open Task Manager** (`Ctrl + Shift + Esc`) and look at the *Processes* tab. Click the **CPU**, **Memory** and **Disk** column headers to sort.
    - One program using nearly all CPU, memory or disk: close it. If it is a normal work app, check for updates.
    - Memory constantly above about 85-90%: too many programs open, or not enough RAM for the workload.
    - Disk at 100% for a long time: often a hard drive struggling, a Windows update installing, or a scan running.
3. **Check free disk space** (File Explorer > This PC). Under about 10-15% free slows Windows down. See the *Disk Space* runbook.
4. **Reduce start-up programs:** Task Manager > *Startup apps*. Right-click non-essential apps with "High" impact and choose *Disable*. Don't disable security software or anything you don't recognise without checking.
5. **Install pending updates:** Settings > Windows Update. Restart afterwards. Updates can also be the reason for temporary slowness right after they install.
6. **Scan for malware:** Windows Security > Virus & threat protection > Quick scan (see the *Malware Cleanup Basics* runbook if anything is found).
7. **Check drive health.** In PowerShell (run as administrator):
    ```powershell
    Get-PhysicalDisk | Select-Object FriendlyName, MediaType, HealthStatus
    ```
    `HealthStatus` should be `Healthy`. Anything else: back up data and escalate.
8. **Check browser extensions:** if the slowness is in the browser, disable extensions one at a time.
9. **Repair Windows system files** (administrator Command Prompt):
    ```
    sfc /scannow
    DISM /Online /Cleanup-Image /RestoreHealth
    ```
    These can take 10-30 minutes. Restart when finished.
10. **Check heat and power:** on a laptop, make sure vents aren't blocked by a soft surface and the power mode isn't set to the lowest setting (Settings > System > Power). Dust in fans causes thermal slowdowns and needs a hardware clean.
11. **Hardware limits:** a PC with 4 GB RAM or a very old hard drive will always be slow with modern software. Record this and recommend a RAM or SSD upgrade or a replacement.

## Escalate when

- Drive health isn't `Healthy`, or the machine makes clicking noises.
- Slowness returns straight after a restart with no obvious cause.
- You suspect malware you can't remove.
- The PC needs a hardware upgrade or replacement (budget decision).
- It affects many users at once (possibly the network, a server or a bad update).

## Ticket note template

```
Issue: PC is slow (all the time / only in <app or site>)
Started: / Recent changes: 
Task Manager top consumer: <process> at CPU __% | Memory __% | Disk __%
Free disk space: __ GB of __ GB | Uptime before restart: 
Actions: restart [Y/N] | disabled startup items [list] | updates installed [Y/N] | malware scan [clean / found] | sfc/DISM [result]
Drive health (Get-PhysicalDisk): 
Result after actions: Improved / No change
Recommendation / next step: 
```