Every installation of Windows 10 comes with Windows Defender Antivirus, so If you suspect that your device is infected, then try running a full virus scan with these steps:
1. Open Start menu.
2. Search for Windows Security and click the top result to open the app.
3. Click on Virus & threat protection.
5. Then Click on the Check for updates option.
6. If there is any antivirus update available, it will install from the Internet.
Once it is up to date:
1. Open the Windows Security window.
2. Select the Virus & threat protection option below the Home option.
3. Select the Scan option.
4. Choose the Full scan option available below the Quick scan option.
5. Click on Scan now.
After you complete the steps, Windows Defender Antivirus should be able to detect and delete/quarantine any malware impacting performance.
Viruses, spyware, adware, and other malicious programs can slow down computers as it takes up a lot of system resources (such as memory, hard drive, and processor) turning a device unusable.