Restart it properly

Windows holds programs and pending updates in memory between sessions. Closing the lid is not the same as restarting. Click Start, then Power, then Restart, and wait for it to come all the way back before you judge the speed.

If you have not restarted in over a week, do this first. It clears more slowdowns than anything else on this list.

Cut down what starts with Windows

Every program that launches at startup takes memory and time. Most of them do not need to.

• Press Ctrl, Shift and Escape together to open Task Manager.
• Click the Startup apps tab.
• Sort by the Startup impact column.
• Right click anything marked High that you do not use daily, then choose Disable.

Disabling a startup app does not uninstall it. You can still open the program whenever you want. If you do not recognise something, leave it alone.

Check your free disk space

Windows needs working room. When the main drive fills up, everything slows down.

• Open File Explorer and click This PC.
• Look at the bar under your C drive.

If less than a tenth of the drive is free, clear space. Open Settings, then System, then Storage, and turn on Storage Sense. Empty the Recycle Bin while you are there. Move large photo and video folders to an external drive if you need more room.

Install the updates you keep postponing

Open Settings, then Windows Update. Install everything on offer, then restart.

Updates carry security fixes as well as performance fixes, so putting them off costs you twice. Set your active hours in the same screen and Windows will install them while you are away instead of interrupting you.

Run a scan you can trust

Windows Security is built in and it does the job. Open Start, type Windows Security, and run a full scan. Let it finish, even if it takes a while.

You do not need to buy a second antivirus. Running two at once usually makes a computer slower rather than safer.

When the problem is the hardware

If the machine still drags after all five steps, look at the drive. An older computer with a spinning hard drive feels slow no matter how clean the software is. Moving to a solid state drive changes how the whole machine feels, and it usually costs far less than replacing the computer.

Check your memory too. Open Task Manager, click Performance, then Memory. If it sits near the top while you work normally, more memory will help.

Still stuck?

Some slowdowns are a symptom rather than the problem. If your PC got slow suddenly, or it slows down only at certain times, something else is going on and it is worth having someone look properly.