A computer that was fine yesterday has turned sluggish. This article answers three questions — where the spending starts, how far you can safely go yourself, and what order to work in.
1. The first six steps cost nothing. Close apps and tabs, update, free disk space, open Task Manager, scan for malware, clear the dust. Money only enters at SSD and RAM.
2. Task Manager tells you whether to spend. Memory high all the time means RAM; the disk at 100% constantly means an SSD. Brief spikes are normal.
3. Check the warranty before you open anything. On a finished product the logic board is covered for two years, and handling judged outside normal use becomes grounds for a chargeable repair.
Each of the three, worked through below.
Money enters at exactly one point
Microsoft's “Tips to improve PC performance in Windows” contains 12 items, and not one of them costs anything. Cost only appears after the list runs out.
| Step | What to do | Cost |
|---|---|---|
| 1 | Close unused apps and tabs; restart if that doesn't help | Nothing |
| 2 | Install OS and driver updates | Nothing |
| 3 | Free up disk space | Nothing |
| 4 | Find the culprit in Task Manager | Nothing |
| 5 | Scan for malware; trim startup apps | Nothing |
| 6 | Check heat and dust | Nothing (beyond cleaning supplies) |
| 7 | Replace the drive with an SSD; add RAM | Chargeable from here |
| Steps 1–6 group items from the Microsoft, Apple and Intel documents in order; the grouping itself is ours. | ||
One more thing to check before step 7: the warranty. A built PC is covered part by part, but a finished product has clear terms.
| Item | Warranty | Within the period |
|---|---|---|
| Computer | 12 months | Performance or function failures in normal use are free |
| Logic board | 24 months — core component | Free for two years from purchase |
| Laptop display | 12 months | Free |
| Samsung's published warranty terms for Korea. Expired warranties, ignoring the manual's cautions, impact damage and non-specified consumables are listed as chargeable — check before opening anything. | ||
Three steps first — apps, updates, disk space
1. Close unused apps and tabs, then restart if needed
This follows Microsoft's item 12 exactly: “Close any apps or tabs you don't need. If performance does not improve, restart your PC.” Sleep and hibernate leave memory as it was, so a full restart is what does the work.
Browser tabs are the culprit remarkably often — Microsoft writes “apps or tabs,” naming tabs separately. Try switching off extensions one at a time too.
2. Check for updates
This is item 1 on Microsoft's list: “Windows Updates often include fixes and performance improvements.” It is normal for things to slow while an update runs, so wait until it finishes before judging — and do not force a shutdown partway through.
3. Check disk space
- Windows: Settings → System → Storage (turn on Storage Sense to clear temporary files automatically)
- Mac: as Apple writes it — “choose System Settings from the Apple menu, click General in the sidebar, then click Storage”
- On a Mac, deleted files do not return space until the Trash is emptied — which is why Apple lists “Empty your Trash” separately.
How much to free is not given as a number in any manufacturer document. That is covered under “What we read into it” below.
See what is eating the resources
Microsoft's item 10 and Apple's document say the same thing — check rather than guess. On Windows, Ctrl + Shift + Esc opens Task Manager; on a Mac it is Activity Monitor. Sort CPU, memory and disk usage highest first.
| If this is high | What it means | Next move |
|---|---|---|
| CPU near 100% | A program has run away, or a malware scan is running | Quit that program, or wait out the scan — free |
| Memory nearly full | Too many programs open, or not enough RAM | Trim tabs and apps → if it is always high, add RAM (paid) |
| Disk at 100% | A background update or backup, or an ageing hard drive | Wait ten minutes; if it is constant, fit an SSD (paid) |
| Nothing is high but it's slow | Performance may have dropped from heat | See the heat section below — free |
| The words that decide whether to spend are “always” and “constant.” A brief spike is normal and no part swap will change it. | ||
Heat — Intel writes “shuts down,” not “slows down”
Intel's wording is a notch stronger than most guides put it.
“Intel Processors have built-in thermal protection. If the processor gets too hot, the built-in protection shuts down the processor.”
The same document lists “evidence of CPU throttling” among the symptoms of overheating. So the sequence is: dropping performance is the signal, and getting hotter still shuts it off.
Intel's own remedy: “check to see if there's an excessive build-up of dust in the system on all the fans, primarily the processor's heatsink fan. If there is, clean it,” and “verify that the intake vents and exhaust vents are clear of dust and lint.” The fan comes first — people often wipe the vents and stop there, but the document points at the CPU heatsink fan.
With a laptop, work on a hard surface. Bedding and laps block the intake. The same principle applies to batteries, covered in making a battery last.
Malware and startup programs
Microsoft writes that malware “can consume CPU and disk resources, which can reduce system performance,” and places it second of twelve. Windows needs no separate product — Windows Security is, in Microsoft's words, “built into Windows, ensuring that your device is protected from the moment you start it up.”
Startup programs are item 5: Task Manager → Startup apps on Windows, System Settings → General → Login Items on a Mac. Microsoft describes the effect as “slow boot time and increase background usage” — meaning slow booting is the main symptom, so if the machine only bogs down hours after starting, this may not be it.
When it is time to spend
| Option | When to move to it | Caveat |
|---|---|---|
| Replace the drive with an SSD | The disk sits at 100% constantly on an older machine | “X times faster” claims were not confirmed in manufacturer documents |
| Add RAM | Memory stays high all the time | Brief spikes are normal |
| Check the disk | An item Apple adds — “If you have problems with your disk, use Disk Utility to verify and try and fix any issues” | A failing disk can be the reason for the slowness |
| Opening the machine | — | Check the warranty first. Handling judged outside normal use becomes grounds for a chargeable repair |
If you are leaning toward a new machine, the electricity bill calculator gives you the running cost of a desktop first. If you are revisiting phone bills at the same time, see cutting telecom costs.
Different symptoms live elsewhere — if it shuts down suddenly, if the display or sound is out, if it won't turn on at all, or if only the internet is down.
Questions that come up
Are you saying not to restart first?
No. It takes seconds and has no downside, so try it. The point is that Microsoft's order shows eleven more things to check when a restart doesn't fix it. Don't stop at “I already rebooted.”
Don't updates make things slower?
While the update runs, yes — it uses disk and CPU. But Microsoft writes that updates include performance improvements and puts them at item 1. Wait until it finishes before judging.
Exactly how much disk space should I free?
No manufacturer document gives a number. Microsoft and Apple both state only that low space reduces performance. Use the warnings and cleanup recommendations your OS raises — Storage Sense on Windows, Storage → Recommendations on a Mac.
Do two antivirus programs really conflict?
Widely repeated, but not confirmed in the Microsoft documents opened here. What is confirmed is only that Windows Security is built in. That said, a scan uses a lot of CPU and disk while running, so if the scan itself is the reason it's slow right now, Task Manager shows it immediately.
Is the order the same on a Mac?
Mostly overlapping, but Apple's document has items Microsoft's list does not — “quit apps that aren't compatible with this Mac” (processor and graphics requirements) and checking the disk with Disk Utility.
When is a service centre the better move?
If all six free steps change nothing and one item stays high in Task Manager constantly, it is a hardware question. On a finished product, check the warranty first — the logic board is covered for two years from purchase.
What we read into it
Microsoft's order runs against the conventional one. “Just restart it” is last (item 12), and not even as a standalone item — it is conditional: “close any apps or tabs you don't need. If performance does not improve, restart your PC.” Meanwhile installing updates is item 1.
The other thing: an earlier version of this article said “keep at least 10–15% of the disk free.” Opening both the Microsoft and Apple documents, no such ratio appears in either. A different Microsoft document — the one on unexpected restarts — does give 10–15% (when it shuts down suddenly). Different document, different symptom.
| Document | What it says about disk space | A number? |
|---|---|---|
| Microsoft — PC performance tips | “Low disk space can reduce system performance” — use Storage Sense and cleanup tools | None |
| Apple — If your Mac runs slowly | “Your computer's startup disk may not have enough free disk space” | None |
| Apple — Free up storage space | Uses only “startup disk is almost full” without defining a threshold | None |
| So the figure was dropped from this article. The widely circulated 10%, 15% and 20% are better read as rules of thumb rather than manufacturer thresholds. | ||
Sources
- Microsoft Support (tier 3, manufacturer document) — Tips to improve PC performance in Windows (checked August 2026). Source for the 12 items and their order — updates first, malware scan second, disk space third, removing unused apps fourth, startup apps fifth, resource monitoring tenth and the restart twelfth — and for every quoted sentence.
- Apple Support (tier 3, manufacturer document) — If your Mac runs slowly (macOS User Guide). Source for “may not have enough free disk space,” checking memory in Activity Monitor, quitting incompatible apps, and Disk Utility.
- Apple Support (tier 3, manufacturer document) — Free up storage space on Mac. Source for the Storage screen path and “Empty your Trash,” and where we confirmed that this document gives no ratio either.
- Intel (tier 3, manufacturer document) — Troubleshooting processor overheating. Source for “built-in thermal protection… shuts down the processor,” “evidence of CPU throttling” appearing among the symptoms, and the heatsink-fan-first cleaning guidance.
- Microsoft Support (tier 3, manufacturer document) — Stay protected with Windows Security. Source for “built into Windows, ensuring that your device is protected from the moment you start it up.”
- Samsung Electronics (tier 3, manufacturer document) — Warranty information (checked August 2026). Source for the 12-month computer warranty, the 24-month core-component warranty on the logic board, 12 months on laptop displays, and the list of chargeable cases.
Where to check further
- The warranty on your own device — terms differ by manufacturer. Check the model on the manufacturer's page before opening anything.
- How much difference an SSD makes — no figure was confirmed in manufacturer documents. The read and write speed specifications published by drive makers are the starting point for a comparison.
- Reference CPU temperatures — the overheating document quoted here defines no specific temperature. Intel's separate temperature document states that the maximum junction temperature limit varies by product and typically sits between 100°C and 110°C, covered in when it shuts down suddenly.
Written as of August 2026. Every quotation is carried from Microsoft, Apple and Intel support documents, the warranty terms come from Samsung's warranty page, and grouping the steps by cost is marked as ours. Menu names and paths vary by OS version and device. Check warranty terms before opening hardware, and take a suspected fault to an authorised service centre.
