Diagnose before you change anything
On Windows, open Task Manager (Ctrl+Shift+Esc) and check the Performance and Processes tabs to see whether CPU, RAM or disk usage is the actual bottleneck. On a Mac, open Activity Monitor from Applications → Utilities and check the same. This takes two minutes and tells you which of the fixes below is actually worth trying first, rather than guessing.
The free fixes, in order
- Trim startup apps: on Windows, Task Manager → Startup apps → disable anything marked 'High impact' you don't need at boot. On Mac, System Settings → General → Login Items & Extensions.
- Clean up storage: keep at least 10-20% of your drive free — once storage gets very full, the operating system struggles to manage temporary files and virtual memory, and everything slows down. Use Windows' built-in Storage Sense or Disk Cleanup, or on Mac, About This Mac → Storage → Manage.
- Check for malware: run a full scan with Windows Defender or your Mac's built-in protections. Background malware quietly eats CPU, RAM and network bandwidth without any obvious symptom.
- Install pending OS and app updates: outdated software is one of the most commonly overlooked causes of slowdown, and updates often include real performance fixes alongside security patches.
- Tame browser bloat: each open tab and each extension runs as its own background process. Aim for a dozen tabs or fewer on an 8-16GB RAM machine, remove extensions you haven't used in the last month, and use built-in tab-sleep features like Chrome's Memory Saver.
- Reduce visual effects: turning off animations and transparency (Windows: Accessibility/System → Visual Effects; Mac: Accessibility → Display → Reduce Motion) frees up a small amount of processing overhead, most noticeable on older hardware.
When a small hardware upgrade is worth it
For a laptop around five years old or more that's otherwise in decent shape, swapping a traditional hard drive for an SSD is repeatedly cited by outlets like PCWorld as the single most impactful upgrade available: boot times commonly drop from two to three minutes down to fifteen to twenty seconds, and everyday file operations that used to take minutes finish in seconds. A RAM upgrade is worth it if the laptop currently has under 8GB and — importantly — the RAM is actually upgradeable, which isn't a given on many recent, thinner laptop designs where memory is soldered directly to the motherboard.
One thing worth knowing before you shop: RAM and SSD component prices rose sharply through 2025 and into 2026, driven by demand from AI data centres. A basic RAM upgrade kit is still realistically available under £40, but a bigger jump — say from 16GB to 32GB — that might have cost £20-40 a couple of years ago has been reported at closer to £150-200 in 2026. Check current prices before assuming the classic 'cheap upgrade' advice still holds at the low end you might expect.
When to just buy a new laptop instead
If your laptop's RAM and storage are soldered and non-upgradeable, if it's failing hardware checks beyond just feeling slow — battery, screen or chassis issues — or if it can no longer receive operating system and security updates, a cheap component upgrade won't fix any of that, and it's genuinely time to consider a replacement. But if it's 'only' slow, and RAM or storage are physically upgradeable, every outlet we've drawn on agrees that's the better-value move to try first.