What are the most common symptoms of viruses?

Some computer viruses alert you to their presence by putting an unexpected message on your screen. Others use more subtle methods.

Things to watch for:

  • programs taking longer to start or running more slowly than usual
  • disk accesses seem excessive for simple tasks
  • access lights turn on for non referenced devices
  • unexplained decreases in the amount of available memory or system resources
  • programs or files mysteriously disappear
  • a sudden reduction in disk space
  • executable files change size and unexplained hidden files appear