In personal computer hardware, calendar year data is managed by the BIOS, which is the basic software that manages inputs and outputs. If the BIOS used cannot handle the year 2000, it will be unable to roll over automatically from 31st December 1999 to 1st January 2000. The date will have to be manually reset in such cases. Models shipped before that time will not be able to roll over automatically to 2000, but for most it will be a simple operation to enable them to handle the year 2000. For example, when booting up a computer for the first time in 2000, the user can follow the instructions in the manual to set the date manually to enable the computer to handle the year 2000.
Some manufacturers supply correction programs on their home pages.
However, there are many manufacturers, and there is the possibility of minor problems in date display and other aspects even in commonly-used software, depending on the version and operating environment. Therefore it is highly important to confirm the manufacturer's compliance for each product. According to a survey conducted in December 1998, all automobile manufacturers state that their products face no y2k problems. A final recheck for confirmation is now under way and each manufacturer will publish its findings. This change may cause problems in some products.