Software that can be run for a limited period of time before it expires. In order to keep running the application, a registration key (password) must be purchased and entered into the trial version, or a new, full version must be installed. Trialware may be set up by date or days. For example, a 30-day trialware program may expire in 30 days or after it has been used for 30 non-contiguous days.Also called "demoware," sophisticated trialware prevents a user from continuously installing new trial versions without paying. For example, it can look for a hidden file or an entry in the Windows Registry that it created when it was previously installed. See shareware and wares.