Many laptops will become slower after some time. If it is going to be annoying, then you could try (subsequently):
- Defragment your disk. An unorganised, fragmented, disk will consume much reading and writing time.
- Run a deep-scan with your anti-virus program.
- Check whether your anti-virus program itself isn’t too heavy. If the settings are, for example: perform a deep scan at every start-up, then this may slow down your device. Some anti-virus programs are too heavy for the machines they are running on.
- Change your system settings. If your machine is in power-saving mode, it is slower.
- Check the Task Manager: are there too many applications running? Also use the result for 4 below.
- Remove suspicious programs and tools.
- Check whether it is only slow while connected to the internet, or always. If only while connected to the internet, then your system might be hacked, and used as a botneck: a “slave” to perform tasks on behalf of others. This might not be caught by your anti-virus program.
- And if nothing helps: back-up your data, write down the license keys of all your installed software, format your entire disk, and re-install using your original Windows license. Install two accounts right away, of which one is not an administrator account. Work by default with this non-administrator account, and only use the administrator account if necessary, for example installing (trusted!) software.