August 14, 2026 · 9 min read
How to speed up your computer: 12 changes, ordered by payoff
A complete checklist for making a slow computer fast again, sorted by how much each change actually gives you per minute spent. Start at the top and stop when it feels fixed.
Most advice on this subject is a list in no particular order, which is how people end up defragmenting an SSD while the actual problem sits untouched. This list is sorted by return: how much speed each change gives you, divided by the effort it takes.
Work down from the top. Stop when the machine feels fine — there is no prize for finishing.
Free, and immediate
1. Reclaim what your browser tabs are holding
On any machine with 8 GB of RAM or less, this is usually the whole answer. Every open tab holds its own memory, and a browser that has been open since Monday is routinely carrying several gigabytes across tabs you have not looked at in days.
You do not have to close them. Chrome can release a tab's memory while leaving the tab exactly where it is, reloading the page when you return — how that works.
2. Restart, if you have not this week
Unglamorous and genuinely effective. Restarting clears leaked memory, stuck processes and pending updates. If you need one every day, note that as a symptom and come back to it.
3. Close what is pinning the CPU
Open Task Manager (Ctrl + Shift + Esc) or Activity Monitor and sort by CPU. If one process is consistently at the top while you are doing nothing demanding, that is your culprit. Identify it by name before closing it.
Ten minutes, once
4. Cut the startup list
Every application that launches at login holds memory all day whether you use it or not. Windows: Task Manager → Startup apps. macOS: System Settings → General → Login Items. Disable what you recognise and do not need daily; leave anything you cannot identify.
5. Audit your browser extensions
Extensions run code inside every page you open, so their cost multiplies by your tab count rather than being fixed. Setting an extension to run only on click, rather than on every site, is often the largest single saving available — how to measure them.
6. Get back to 15% free disk space
Both operating systems need working room, and a nearly full drive is measurably slower. Empty the trash, clear the Downloads folder, and use the built-in storage tools rather than a third-party cleaner.
7. Uninstall what you stopped using
Not for the disk space — for the background services, updaters and helpers that came with it and still run at every login.
Half an hour, or a bit of money
8. Clear the vents
If the machine is quick for ten minutes and sluggish after thirty, it is throttling to protect itself from heat. Dust in a laptop heatsink is the usual reason, and no software setting overrides physics.
9. Check the drive's health
Uniform slowness with no trigger — slow boot, slow app launches, slow file operations — points at the disk. Drives degrade gradually rather than failing cleanly, and a dying one feels exactly like an old computer.
10. Replace a mechanical hard drive with an SSD
The single largest improvement available to an older machine, by a distance. It also softens memory pressure, because swapping to an SSD is far less painful than swapping to a spinning platter.
11. Add RAM, if you are actually swapping
Check first. If your system is not paging to disk, more RAM changes nothing. If it is, this fixes the problem at the root. Many recent laptops solder their memory down, so confirm yours is upgradeable before buying anything.
12. Reinstall the operating system — last
It works, and it is a weekend. Do it once you know the cause, not as a substitute for finding out, or you will rebuild your way back to the same problem in six months.
What is not on the list
Registry cleaners, driver updaters and “optimiser” suites do not address memory pressure, disk health or heat, which between them explain nearly every slow computer. Defragmentation is meaningless on an SSD and automatic on Windows for spinning disks. Disabling system services you cannot identify creates new problems rather than solving old ones.
If you would rather diagnose than work through a list, the four causes and how to tell them apart will get you to the right item on this page in about two minutes.
Common questions
- What is the fastest way to speed up a computer?
- Reclaim the memory your browser is holding. It costs nothing, takes seconds, and on a machine with 8 GB or less it is usually the entire problem.
- How often should I restart my computer?
- Once a week is plenty for a healthy machine. Needing one daily is a symptom worth investigating rather than a maintenance routine.
- Does deleting files speed up a computer?
- Only if the drive is nearly full. Both Windows and macOS slow down without free working space, so getting back to roughly 15% free helps. Deleting files on a half-empty drive changes nothing.
- How much does adding RAM help?
- Enormously if you are currently swapping to disk, and not at all if you are not. Check whether your system is paging before spending money — that single check tells you whether RAM is your bottleneck.
- Are free PC cleaner tools safe?
- The category has a long history of bundled adware and invented problems. Nothing they do addresses memory pressure, disk health or thermal throttling, which is what actually slows machines down.