In computer software, a time bomb is part of a computer program that has been written so that it will start or stop functioning after a predetermined date or time is reached. The term "time bomb" does not refer to a program that stops functioning a specific number of days after it is installed; instead, the term "trialware" applies. Time bombs are commonly used in beta (pre-release) software when the manufacturer of the software does not want the beta version being used after the final release date. One example of time bomb software would be Microsoft's Windows Vista Beta 2, which was programmed to expire on May 31, 2007.[1] The time limits on time bomb software are not usually as heavily enforced as they are on trial software, since time bomb software does not usually implement secure clock functions.