YOU MIGHT HAVE A VIRUS IF...

In addition to the symptoms just explained, there are also some iffy symptoms. The following could potentially point to a virus infection, but they could also be symptoms of other problems instead:

  • Windows will not start at all, even though you have made no system changes, installed or removed any programs, or made any Registry edits since the last time it started successfully.
  • Windows will not start because certain critical system files are missing (and you see an error message listing which files those are), and you're sure you did not delete them accidentally yourself.
  • The computer starts up normally sometimes; other times it hangs before the desktop icons and taskbar appear.
  • The computer runs very slowly and/or takes a long time to start up.
  • Out-of-memory error messages appear even though you have plenty of RAM (random access memory).
  • Viewing the system processes (Task Manager will work for this -- press Ctrl + Alt + Delete, and then click the Task Manager button) shows that a high percentage of the CPU (central processing unit) time is being consumed by an unknown process.
  • New applications don't install properly.
  • When you view the Task Manager, there are programs or processes running that you don't recognize, even after shutting down all running programs and system tray utilities.
  • Windows spontaneously reboots for no apparent reason.
  • Applications that used to run normally are crashing frequently now. Removing and reinstalling them does not solve the problem.
  • A disk utility such as Check Disk (covered in Lesson 5) reports multiple serious disk errors.
  • A disk drive completely disappears from Windows.

Often, a key to distinguishing virus-related system problems from ordinary ones is situational. What did you do right before the problem started? If possible, check your email inbox to see whether an email containing a virus might still be hanging around there. Check your Deleted Items folder as well, and your Sent Items folder for evidence of having spread the virus to others.