How to Fix a Slow Computer (Windows & macOS)

Aug 07, 2025

Overview

If your computer is running slower than usual, there are several steps you can take to improve its performance. This guide walks you through simple troubleshooting steps for both Windows and macOS systems.

Basic Checks (All Systems)

Restart Your Computer
If you haven't restarted your computer in a while, start here. A reboot can clear temporary files and refresh system resources.
Close Unused Programs
Too many open applications can slow down your computer. Close anything you're not actively using.
Check for Software Updates
Ensure your operating system and software are up to date. Updates often include performance improvements and bug fixes.

For Windows Users

1. Check Task Manager

Press Ctrl + Shift + Esc to open Task Manager.
Click the Processes tab.
Look for programs using high CPU, Memory, or Disk resources.
Right-click on any non-critical task and choose End Task.

2. Disable Startup Programs

Press Ctrl + Shift + Esc > Startup tab.
Right-click and disable unnecessary programs that start with Windows.

3. Run Disk Cleanup

Search for Disk Cleanup in the Start Menu.
Select your drive (usually C:) and clean temporary files.

4. Check for Malware

Run a full system scan using Windows Defender or a trusted antivirus tool.

5. Defragment Your Hard Drive (HDD only, not SSDs)

Search for Defragment and Optimize Drives.
Select your hard drive and click Optimize.

For Mac Users

1. Check Activity Monitor

Open Applications > Utilities > Activity Monitor.
Sort by CPU or Memory usage to identify any resource hogs.
Force quit any app you don’t need using the X button.

2. Manage Startup Items

Go to System Settings > Users & Groups > Login Items.
Remove unnecessary items from the startup list.

3. Free Up Disk Space

Click the Apple menu > About This Mac > Storage > Manage.
Review and remove unneeded files and apps.

4. Reset PRAM and SMC (For Intel Macs only)

Sometimes resetting system settings can help performance. Apple's guide here.

5. Run Malware Scan

Use a reputable Mac antivirus to scan for malware or adware.

When to Contact IT Support

If your computer is still slow after trying these steps, contact the IT department with the following information:

Computer make/model
Operating system
Description of the issue
When the issue started
Steps already attempted

Need Help?
Submit a ticket or call the IT Help Desk at 616.395.7670 for further assistance.