For example, many programs calculate the age of a person by
substracting current year from the birth year (for example,
97-65 = person is 32 years old). Such a calculation on January
1st, 2000 would tell that this person is -65 years old.
More information on these problems is available in the web at
To learn more on how F-Secure' products work on and after year
2000, please read http://www.F-Secure.com/news/year2000.shtml
Suprisingly, there are very few computer viruses which activate
during new year 2000, and none of them is known to be in the wild.
Do note that exists some trojans that try do to something related
to Y2K. These have nothing to do with the Y2K problem itself.
For an example, see Y2KCount trojan at:
[Mikko Hypponen, F-Secure]