Nagware, also called guiltware or annoyware, is a pop-up reminder that appears with trial versions of computer programs. Many trial versions of games, programs or additional features use nagware to alert the user to pay or register after the trial period has expired. The term derives its name from its function of “nagging” the user to take a specific action.

Many programming companies like to offer short trial periods of their software, understanding that a user may not be willing to buy the program unless they can fully explore it. These trials, called shareware, allow either full program access or a stripped down version of the program. Most shareware trials have a time limit on them, either of total minutes the program is used, or a set period of time, usually no more than 30 days. After this limit is up, attempts to open or close the program result in nagware windows.

A nagware window, or nag screen, usually takes the form of a pop-up, often blocking any activity related to the program other than closing the application or taking a specific action dictated by the nagware. Most often, the window will link the user to a website where they can purchase a full version of the application they have been trying. Users should to be wary as some computer viruses can mimic nagware in an attempt to get credit card or other personal information. Always be sure to check out the security features of a website before typing in any personal data.

Some users look for ways to circumnavigate nagware. This involves the use of “crack codes” to hack into the security features of the program and fool it into believing payment has been made. Users should be warned that this type of hacking is usually illegal, as it violates anti-piracy laws. Additionally, as the hacking approach often involves deleting key files, it may cause not only the program to operate incorrectly, but might also destroy something needed for your computer to run normally.

To avoid nagware legally, some websites, like Yahoo! Games, offer online versions of their programs that can be used on an unlimited basis. Often, the games will be only the basic version, as the companies want to withhold advanced features for those who actually pay for the game. Still, using online game versions allows you to enjoy a program at your leisure, without being concerned about time limits and nagware.