Almost every “my laptop is slow” job that comes across our bench falls into one of six causes. Work through these in order before you spend money on anything.
1. Check what’s actually using your resources
Open Task Manager on Windows (Ctrl+Shift+Esc) or Activity Monitor on a Mac, and sort by CPU and Memory. If one process is pinned near 100% constantly, that’s your answer — it might be a browser with too many tabs, a stuck update, or something worth investigating further rather than a hardware problem at all.
2. Check how full your main drive is
A drive that’s over roughly 90% full slows down noticeably, especially if it’s a traditional hard drive rather than an SSD. Clearing space, or moving to a larger SSD, often solves “slow” complaints on its own.
If your laptop is more than five years old and still running on its original hard drive, an SSD upgrade is usually the single most effective fix available — often more noticeable than buying a new laptop entirely.
3. Check what launches at startup
Too many programs opening automatically is one of the most common causes of a slow-feeling machine, particularly right after login. On Windows, the Startup tab in Task Manager shows what’s enabled and its impact rating — disable anything you don’t recognise or use daily.
4. Run a malware check
Unexplained slowness, especially combined with pop-ups, browser redirects, or a fan that runs constantly even when idle, is a classic sign of malware. Run a full scan with Windows Security (built in and free) or your preferred antivirus tool.
5. Check you have enough memory
If the machine stutters when you have several browser tabs or programs open, it may simply be short of memory (RAM). In Task Manager, open the Performance tab and select Memory: if it sits above about 90% in normal use, more RAM will help. 8GB is the realistic minimum for Windows 11 today, and 16GB gives comfortable headroom for multitasking. Many desktops and some laptops can be upgraded cheaply.
6. Make sure it isn’t overheating
When a processor gets too hot, it deliberately slows itself down to protect itself. A fan that roars, a hot base or a machine that slows down after a few minutes of use all point to dust or dried-out thermal paste. See our guide to laptop overheating and noisy fans for safe fixes.
When it’s worth booking a diagnosis instead
If you’ve been through all six checks and nothing’s changed, it’s likely a hardware-level issue — a failing drive, thermal paste that’s dried out and is causing the CPU to throttle, or a battery fault putting the machine into a reduced power state. These need proper diagnostic tools to confirm, which is where we come in.
Book a free diagnosis or see our Laptop Repair page for pricing.