What steps should be taken in diagnosing and identifying viruses? (Computer virus)

Most of the time, a virus scanner program will take care of that for
you. To help identify problems early, run a virus scanner:

1. On new programs and diskettes (write-protect diskettes before
scanning them).
2. When an integrity checker reports a mismatch.
3. When a generic monitoring program sounds an alarm.
4. When you receive an updated version of a scanner (or you have
a chance to run a different scanner than the one you have
been using).

Because of the time required, it is not generally advisable to set a
scanner to check your entire hard disk on every boot.

If you run into an alarm and your scanner doesn't identify anything or
doesn't properly clean up for you, first verify that the version you are
using is the most recent. Then get in touch with a reputable antivirus
researcher, who may ask you to send in a copy of the infected file.
(Also see C9; and F4 if you decide you need to ask for help on Virus-
L/comp.virus.)