It depends upon the type of virus:
For Malware:
- Your computer takes much time in starting up.
- Even after starting computer you realize that computer is freezing a lot or at least it is slower than it should be.
- Your computer will experience BSOD (Blue Screen Of Death) where your computer will crash and restart.
- You see annoying Ads on your desktop and on your web browser.
- Your Antivirus software goes inactive or disappears.
- You see, often, unknown tab openings and unknown site access without your access.
- Unknown apps in Task manager
- Unknown programs in folders, especially without icons.
- A lot of random activities on your desktop.
- Change in folder options.
- High network activity even if you are not doing anything.
For Spyware:
- Hard to say, not much, you might feel computer slowdown or not. El spyware no causa ninguna destrucción, sólo recoge sus datos personales y los envía a su anfitrión (creador del virus).
Para el Ransomware:
- Todos sus archivos están encriptados (lo que significa que no puede acceder a ellos). Usted ve una ventana de la aplicación diciendo que si usted no paga la cantidad prescrita de dinero sus archivos serán eliminados y habrá un temporizador de cuenta atrás que es el ultimátum dado a usted.