A slow computer can have more than one cause. Limited storage, too many apps opening at sign-in, software that needs attention, or aging hardware may play a part. Start by noticing what is slow before changing settings.
Is it one thing, or everything?
Write down what you notice. Is a single website slow? Does one app take a long time to open? Or does the whole computer respond slowly? This small distinction gives you a clearer question to work with and makes it easier to explain the problem to someone else.
Start with a small, reversible step.
Save your work. Close an ordinary app or browser tab you are not using, then see whether anything changes. A normal restart can also be a reasonable step when no update or other important operation is in progress. Do not force the power off just to make a slow screen disappear.
Look before clearing space.
Your computer’s storage settings can help show whether the drive is nearly full. Reading the information is different from agreeing to a cleanup. Do not delete an unfamiliar folder or remove important files merely because a tool describes them as large.
Keep a useful note.
Record what was slow, when it happened, and the one thing you tried. Avoid changing several settings at once. A small record can help you tell whether something improved or whether you need more help.
Know when to stop.
If the computer keeps crashing, important files are missing, or you are unsure what a proposed change will do, ask an appropriate professional. There is no honest one-click promise that every slow computer can be made new again.