A slow PC is one of the most common IT frustrations — and one of the most fixable. Which? has published a practical guide covering eight things you can do right now to speed up a sluggish Windows PC or Mac, without spending anything or calling in a specialist. We have expanded on their recommendations with some additional context from a business IT perspective.
1. Disable Startup Apps
Every application that launches automatically when you switch on your PC adds to your boot time and keeps consuming RAM in the background even when you are not actively using it. Over time, as software is installed, the startup list quietly grows — until you find yourself waiting a couple of minutes just to get to a usable desktop.
On Windows: Open Task Manager (Ctrl + Shift + Esc), go to the Startup apps tab, and disable anything you do not need immediately on boot. Right-click any item to see its impact rating. On Mac: Go to System Settings → General → Login Items and remove anything unnecessary.
Keep your security software enabled in startup. Everything else is worth reviewing.
2. Turn Off Unnecessary Visual Effects
Windows and macOS both include animations, transparency effects, and shadow rendering that look polished but consume CPU and GPU resources. On an older or lower-spec machine, disabling these can produce a noticeably snappier feel.
On Windows: Search for Adjust the appearance and performance of Windows in the Start menu, then select Adjust for best performance or manually untick the effects you want to remove. On Mac: Go to System Settings → Accessibility → Display and enable Reduce Motion and Reduce Transparency.
3. Scan for Malware
A machine running slower than usual without obvious reason — particularly if it is also running hotter or the fan is constantly active — can be a symptom of malware. Some malicious software is designed to run quietly in the background, using your CPU and network connection for its own purposes.
Run a full scan with your security software. On Windows, Microsoft Defender is built in and free — search for Windows Security and run a full scan. Also use the built-in Windows troubleshooters (Settings → System → Troubleshoot) to identify and fix common performance issues automatically.
4. Check Your Power and Battery Settings
On laptops, Windows and macOS sometimes throttle CPU performance to save battery life — particularly if you are on Battery Saver mode. If your laptop feels sluggish when unplugged but fast when charging, this is the likely cause.
On Windows: Click the battery icon in the taskbar and move the power slider toward Best Performance when you need full speed and have access to a charger. On Mac, Battery settings are under System Settings → Battery.
5. Look After Your Battery Health
As laptop batteries degrade, Windows and macOS may automatically throttle CPU performance to keep the system stable within the power the battery can deliver. A battery that once lasted five hours now barely managing two is also a sign the battery is degrading.
Best practice is to keep charge levels between 20% and 80% where possible, and if storing a device unused for a long period, charge it to around 50% first. Many modern laptops include battery health management settings that do this automatically.
6. Upgrade to an SSD
If your PC is more than five years old and still running a traditional mechanical hard drive (HDD), this single upgrade will make a more dramatic difference than anything else on this list. SSDs have no moving parts, access data almost instantly, and make boot times, application launches, and file operations feel completely different.
To check what you have: open Task Manager, go to the Performance tab, select your disk, and look for the drive type label. On Mac, go to Apple menu → About This Mac → More Info → Storage.
Swapping an HDD for an SSD in a compatible laptop or desktop is often significantly cheaper than replacing the whole machine — and can give a four or five-year-old device several more productive years of life. If you are not comfortable performing the upgrade yourself, this is exactly the kind of job BIT Tech can handle for you.
7. Keep Your Operating System Updated
Operating system updates are not just security patches — they frequently include performance improvements, driver updates, and fixes for bugs that cause slowdowns. Keeping Windows and macOS up to date is one of the simplest things you can do for both speed and security.
One important note: Windows 10 reached end of support on 14 October 2025. If you or your team are still running Windows 10, you are no longer receiving security updates, which is a significant risk. Devices that support Windows 11 should be upgraded; devices that do not may need replacing.
8. Update Your Apps and Programs
Outdated applications can be slow, unstable, and vulnerable to security exploits. Keeping software current ensures you benefit from performance improvements and the latest security patches. On Windows, the Microsoft Store handles updates for Store apps; other applications typically have their own update checks within the Help or Settings menus. On Mac, the App Store manages most updates.
When to Consider Replacing Rather Than Fixing
Not every slow PC is worth repairing. Which? recommends considering replacement when:
- The operating system is no longer supported and the hardware cannot run a supported version
- The device is five or more years old and requires a significant repair
- The battery no longer holds adequate charge and cannot be replaced
For businesses, there is also a productivity cost to running aging hardware that is harder to quantify but very real. A staff member waiting two minutes for their laptop to boot, or experiencing frequent freezes, loses time every single day. Sometimes the most cost-effective decision is a hardware refresh rather than continued maintenance.
Through our partnership with TechNest-Global, BIT Tech can source new and quality-assured refurbished laptops from brands including Dell, HP, Lenovo, and ASUS at competitive prices — with full setup, migration, and ongoing support included. Get in touch if your team’s hardware is due a refresh, or if you need help diagnosing and fixing a slow machine.
