how do you know if you have a virus on your laptop?
['Unexpected pop-up windows. Unexpected onscreen ads are a typical sign of a virus infection. ... ', 'Slow start up and slow performance. ... ', 'Suspicious hard drive activity. ... ', 'Lack of storage space. ... ', 'Missing files. ... ', 'Crashes and error messages. ... ', 'High network activity. ... ', 'Email is hijacked.']