Your computer used to boot in twenty seconds. Now you press the power button, make a coffee, and it is still thinking about it. A slow computer is rarely “just old” · in almost every machine we see at Dtech IT Solutions, the slowdown traces back to one of five fixable causes, and most of them cost far less to fix than a new PC.
Why your computer actually slowed down
Hardware does not get slower with age. The chips inside your PC run exactly as fast as the day you bought it. What changes is everything around them: the operating system gets heavier with each update, apps quietly add themselves to startup, the drive fills up, dust chokes the cooling, and browsers accumulate extensions you never asked for.
So the useful question is not “how old is this thing” but “what is the bottleneck right now”. In the machines that come through our computer repair service across Melbourne, Geelong and Newcastle, that bottleneck is almost always one of five things. Work through them in order and you will usually find the culprit inside half an hour.
The 15 minute check anyone can do
Before you spend a cent, let the computer tell you what is wrong. On Windows, press Ctrl + Shift + Esc to open Task Manager and click the Performance tab. On a Mac, open Activity Monitor from Applications then Utilities.
- Disk sitting at 100 percent while you do almost nothing · your drive is the bottleneck. Go to cause 1.
- CPU high with a long list of apps you did not open · startup and background clutter. Go to cause 2.
- Memory above roughly 85 percent with normal use · you are short on RAM. Go to cause 4.
- Fans roaring and the machine hot to touch, with speed dropping after ten minutes · heat. Go to cause 5.
- Pop-ups, unfamiliar toolbars, a search engine you did not choose · malware. Go to cause 3 immediately.
Also check free space. If your C: drive has less than about 10 percent free, Windows has nowhere to put temporary files and everything crawls. Clearing space is free and takes minutes.
Cause 1: an old spinning hard drive
This is the big one. If your PC or laptop is more than about six years old and was not sold as a premium model, there is a good chance it still has a mechanical hard drive: a physical platter spinning at 5,400 rpm with an arm reading it. Modern Windows was never designed for that. An SSD has no moving parts and reads data many times faster, which is why a five year old laptop with a fresh SSD can feel quicker than a cheap new one that still ships with a spinning disk.
Signs you are looking at a drive problem: boot takes minutes rather than seconds, the disk light stays solid, opening File Explorer or Outlook makes everything else freeze, and Task Manager shows disk at 100 percent while CPU sits low.
An SSD upgrade with your files, apps and Windows cloned across is the highest value repair in our workshop. If the old drive is also making clicking or grinding noises, stop using it and read about data recovery before you do anything else · a failing drive that is still being used is a drive you are running out of time with.
Cause 2: startup programs and background apps
Every printer suite, cloud sync tool, game launcher and updater you ever installed wants to load with Windows. Individually they are small. Twenty of them together mean your first five minutes after login are spent competing with software you did not ask to run.
Open Task Manager and click the Startup apps tab. Disable anything you do not need the second the machine turns on: manufacturer update tools, Spotify, Teams if you only use it occasionally, printer dashboards, “PC cleaner” utilities. Disabling a startup item does not uninstall the app · you can still open it whenever you like.
While you are there, look at your browser. Ten extensions and forty open tabs will slow down any computer, no matter how new it is. Each tab is effectively its own little program holding memory.
Cause 3: malware, adware and browser junk
Not every infection announces itself. Plenty of modern adware just sits in the background serving ads, mining crypto or redirecting your searches, and the only symptom the owner notices is that the machine “got slow”. If your homepage changed on its own, if you see pop-ups outside the browser, or if a program you never installed is asking for permission, treat speed as a secondary problem and clean the machine first.
Run a full scan with Microsoft Defender, and keep the operating system patched · the Australian Signals Directorate’s advice on updating your devices is the plain-English standard here. If the machine is already compromised, a scan alone may not be enough; our virus and malware removal service exists for exactly the cases where the infection reinstalls itself after every reboot.
Cause 4: not enough RAM for how you work
RAM is your computer’s desk space. When the desk is full, Windows starts shuffling things to the drive instead, which is dramatically slower · and if that drive is a mechanical one, you now have two problems compounding each other.
A machine with 4 GB will struggle with Windows 11 and a browser, full stop. 8 GB is the realistic floor for everyday home use in 2026. If you keep Office, Teams, a dozen tabs and a photo editor open together, 16 GB is where things stop feeling tight. Many desktops and a good number of business laptops can be upgraded for well under the price of replacing the machine, though most thin ultrabooks have RAM soldered to the board and cannot be changed. Checking that before you buy anything is worth a phone call.
Cause 5: heat, dust and thermal throttling
Processors protect themselves. When they get too hot, they deliberately slow down rather than cook, and that is called thermal throttling. The classic pattern: the computer is fine for the first ten minutes, the fans get louder, and then everything turns to treacle.
Melbourne homes are dusty, and laptops that live on beds, couches and carpet block their own intake vents. Every few years the heatsink fins clog and the thermal paste between the chip and the cooler dries out. A proper internal clean and a repaste is a workshop job on most laptops, but it can restore full performance to a machine the owner had already written off. In the meantime, use it on a hard flat surface and keep the vents clear.
Repair, upgrade or replace?
Our rough rule: if the machine is under about eight years old, has a working screen and keyboard, and the only real problem is speed, upgrading is almost always the better value. An SSD and a RAM top-up will typically buy you another two to four years of comfortable use for a fraction of the cost of a new computer.
Replacement makes more sense when the hardware cannot run a supported version of Windows, when the battery, hinges and keyboard are all going at once, or when repeated failures suggest the board itself is tired. If you are in that position because your PC cannot make the jump to Windows 11, our guide to Windows 10 end of life and your safe upgrade options walks through the choice properly. And if you do buy new, we can handle the new computer setup and data transfer so nothing gets left behind on the old machine.
Whichever way you go: back up first. Upgrades are routine, but drives that are already struggling are the ones most likely to give up during the process.
If your machine is still crawling after these steps, a hands-on diagnosis is the fastest path. We offer same-day visits across Melbourne, from Carlton to Brighton.
Frequently asked questions
Will adding an SSD really make my old laptop feel new?
For most machines still running a mechanical hard drive, yes · it is the single most noticeable upgrade available. Boot times drop from minutes to seconds and apps stop hanging. It will not make an underpowered processor faster, but processor speed is rarely what people are actually complaining about.
Do those “PC cleaner” and “speed booster” programs work?
Almost never, and many of them are the problem. Free registry cleaners and optimisers often bundle adware, nag you into paid upgrades, and deliver no measurable speed gain. Disabling startup items and clearing disk space achieves more, for nothing.
How much free disk space should I keep?
Aim for at least 15 to 20 percent of the drive free. Below 10 percent, Windows starts running out of room for temporary files, updates and virtual memory, and the whole system slows regardless of how good the hardware is.
Can you fix a slow computer at my home?
Yes. Most diagnostics, cleanups, malware removal and startup tuning are done onsite at your place. SSD swaps, RAM upgrades and internal cleans are often done onsite too, though some laptop models come back to the workshop. We cover Melbourne, Geelong and Newcastle, seven days a week.
How much does it cost to find out what is wrong?
Home visits start at $59 and business callouts at $89. We tell you what the machine needs and what it will cost before any work goes ahead · if the honest answer is that it is not worth repairing, we will say so.
If your computer has slowed to a crawl and you would rather someone just sorted it out, we can help. Book online or call 03 7033 2634 · 8am to 8pm, seven days. Email [email protected].
Related: Computer Repairs · Virus Removal · Data Recovery · Computer Repairs Melbourne