How To Know if Your Computer Has a Virus

Think you have a computer virus? Look for these telltale signs, then take these steps.

Here are some of the tell-tale signs that your computer may exhibit if it's infected by a virus.

  • Changes in the length of programs
  • Changes in the file date or time stamp
  • Longer program load times
  • Slower system operation
  • Reduced memory or disk space
  • Bad sectors on your hard drive or SSD
  • Unusual error messages
  • Unusual screen activity
  • Failed program execution
  • Failed system bootups when booting, or accidentally booting, from the A: drive.
  • Unexpected writes to a drive.

What else can I do to stop a computer virus?

These symptoms don't guarantee that a virus is present; there are many other possibilities that can cause them. To determine if it's a virus follow these steps recommended by Burrell:

1. Get the most recent version of a quality anti-virus program on a computer that's behaving normally; install it on a clean floppy and write protect the diskette. Boot the suspect computer with a clean bootable diskette and run the anti-virus program from the newly created disk.

If the program gives you the option to use heuristics, enable them only after the initial scan finds nothing and then scan again. (But don't turn on heuristics during the first scan, because they will increase the probability of false alarms.)

2. If nothing shows up, consider contacting the support center of the anti-virus program for further direction.

Found a virus? Most of the experts we consulted said not to rely on the anti-virus to clean the infected file. Instead, replace it with the original clean version.

Some of the material in this article comes from Wolfgang Stiller the developer of Integrity Master anti-virus program and Nick FitzGerald editor of Virus Bulletin.