While imaging is a reaction to software changes that have adversely affect the performance of a system, freezing is a strategy that prevents software problems from occurring. A technician installs the application that provides the freezing function and then configures the system exactly as he or she wants it to function. Just like imaging, all updates and applications are installed and the network configuration along with network printers and others peripherals are installed. Once the configuration is confirmed, the technician calls the freezing software (which is running in the background, unseen by the user) and enters a password which provides access to the controls that can be used to change the state of the computer to “frozen” and restarts the computer. Until it is “unfrozen” by a user who provides the password, then each time the computer is restarted, it returns to the state when it was frozen.
As software to freeze computers has been used, additional features have been added. For example, the directories in which operating systems updates are installed can be left “unfrozen” so that necessary updates are not deleted when the computer is restarted. Also, some user directories can be unfrozen, so that documents created by users can be saved to a frozen computer. While it does prevent many software-induced problems, there are several reasons that IT managers may avoid using this solution:
- Commercial software to freeze computer can be very expensive;
- Unless the version of the software allows for unfrozen directories, it necessitates files be stored on systems other than the local frozen hard drive;
- Unless properly configured, it can remove critical system updates or data;
- As hard drives have approached and exceeded terabytes of storage, the freezing process can lead to noticeable delays in start-up which interfere with the perceived performance of computers in many school settings.