<P> The Michelangelo virus is a computer virus first discovered on 4 February 1991 in Australia . The virus was designed to infect DOS systems, but did not engage the operating system or make any OS calls . Michelangelo, like all boot sector viruses, basically operated at the BIOS level . Each year, the virus remained dormant until March 6, the birthday of Renaissance artist Michelangelo . There is no reference to the artist in the virus, and it is doubtful that the virus writer intended Michelangelo to be referenced to the virus . The name was chosen by researchers who noticed the coincidence of the activation date . The actual significance of the date to the author is unknown . Michelangelo is a variant of the already endemic Stoned virus . </P> <P> On March 6, if the PC is an AT or a PS / 2, the virus overwrites the first one hundred sectors of the hard disk with nulls . The virus assumes a geometry of 256 cylinders, 4 heads, 17 sectors per track . Although all the user's data would still be on the hard disk, it would be irretrievable for the average user . </P> <P> On hard disks, the virus moves the original master boot record to cylinder 0, head 0, sector 7 . </P>

When does the michelangelo virus take effect every year