Computers slow down over time. It's frustrating, but it's not inevitable — and in most cases, it's fixable. The key is understanding why your PC is slow, because the right fix depends entirely on the cause. Some slowdowns are pure software — a quick cleanup can transform performance. Others are hardware-related, where no amount of software tweaks will make a significant difference.
This guide walks you through the most common causes of a slow Windows PC, starting with the quick free fixes and moving through to hardware upgrades. Work through it in order — you might be surprised how much difference the early steps make.
Step 1: Check What's Using Your Resources
Before anything else, open Task Manager (Ctrl + Shift + Esc) and click the "Performance" tab. Check your CPU usage, RAM, and disk activity. If your disk is constantly at 100%, that's often the culprit — and the solution is usually an SSD upgrade (more on that below). If CPU usage is perpetually maxed out, something is hogging processing power — the "Processes" tab will show you what.
Also check how much free RAM you have while the computer is in normal use. If you have less than 1–2GB free, you're running out of memory and the computer is using the hard drive as a slow substitute — which destroys performance.
Step 2: Disable Startup Programs
One of the most common causes of a slow computer — especially slow boot times — is too many programs starting up automatically. Every time you install software, it often adds itself to the startup list. Over years, this list grows enormous.
Open Task Manager, click the "Startup" tab, and look at what's there. Right-click and disable anything you don't need running immediately at startup. Be careful — don't disable anything you don't recognise. When in doubt, leave it.
After doing this, restart your computer and notice the difference. Many people are astonished by how much faster it boots.
Step 3: Clean Up Storage
A hard drive that's nearly full slows down significantly — especially older spinning hard drives. Windows also uses free disk space for virtual memory and temporary files. If you're running low, clear some space.
Run the built-in Disk Cleanup tool (search for it in the Start menu). Check all the boxes and run it. For a deeper clean, you can also clean up system files through the same tool. Also check your Downloads folder — it accumulates gigabytes of forgotten installers over the years.
Step 4: Check for Malware
Malware — viruses, spyware, cryptocurrency miners — is a very common cause of computer slowdowns. Some infections are designed to use your computer's resources quietly in the background. Run a full scan with Windows Defender (built in) and also consider running a second scan with Malwarebytes Free.
If you're finding lots of infections, or if your antivirus keeps finding and re-finding the same threats, the infection may be too entrenched for simple removal. At that point, it's worth bringing your computer to us at PC Madness for a thorough professional clean.
Step 5: Keep Windows Updated
Windows updates include performance improvements and security fixes. Running an outdated version of Windows can leave you vulnerable to malware and miss optimisations that improve speed. Go to Settings → Windows Update and make sure you're current. Microsoft also publishes official tips to improve PC performance in Windows if you want to go deeper.
Also update your drivers — particularly graphics card drivers, which can significantly affect performance. Modern GPU drivers from Nvidia and AMD include performance optimisations that older drivers don't have.
Step 6: Adjust Power Settings
If your computer is set to "Power Saver" mode — or if it's a laptop running on battery — Windows deliberately throttles performance to save power. Change your power plan to "Balanced" or "High Performance" to get full speed. Find this in Control Panel → Power Options.
Step 7: Upgrade to an SSD (Game Changer)
If your computer still has a spinning hard drive (HDD) rather than a solid-state drive (SSD), this is by far the single most impactful upgrade you can make. The performance difference is extraordinary — boot times typically drop from 2–3 minutes to under 15 seconds, and everything from opening files to launching applications becomes dramatically faster.
SSDs are now very affordable. A 500GB or 1TB SSD costs a fraction of what they did even five years ago. At PC Madness in Midland, we can clone your existing drive to a new SSD — so all your files, programs, and settings transfer exactly. You don't lose anything and don't have to reinstall anything.
If you're running Windows on a spinning HDD and wondering why your computer is so slow — this is almost certainly a major part of the answer.
Step 8: Add More RAM
If Task Manager shows your RAM regularly at 80–90% or higher, you need more memory. Adding RAM is particularly effective if you tend to have lots of browser tabs, multiple applications, or use demanding software.
Most computers running Windows 10 or 11 work well with 8GB of RAM for general use, or 16GB for heavier workloads. If you're on 4GB, you're going to feel it — upgrading to 8GB will make a noticeable difference.
Step 9: Consider a Clean Windows Reinstall
If you've tried everything else and the computer is still sluggish, a clean reinstall of Windows can help. Over years of use, Windows accumulates cruft — orphaned registry entries, partial uninstalls, corrupted files, and accumulated background processes that slow things down. A fresh install removes all of that and gives you a clean, fast baseline.
We do this regularly at PC Madness — we back up all your files first, perform a clean install, reinstall your programs, and return everything to you working properly. It can make an older computer feel brand new.
When Software Fixes Aren't Enough
If you've worked through all these steps and your computer is still frustratingly slow, the hardware may simply be too old to run modern software efficiently. A 10-year-old processor with 4GB of RAM and a spinning hard drive is going to struggle with current versions of Windows and Chrome regardless of how well it's maintained.
At that point, the options are: upgrade the hardware (SSD + RAM is often enough), or consider whether it's time for a new or refurbished machine. If you're not sure which way to go, bring your computer in to PC Madness at 2C Stafford Street, Midland. We'll give you an honest assessment and recommend the most cost-effective path.
Need help speeding up your PC? Call PC Madness on 08 9250 4554 or drop in to our Midland workshop. We're here Monday to Friday, 8am–4pm.