question: Why does turning a computer off and back on again fix the issue? Like doesn't it indicate a problem that will happen in the future?
comment: It depends on what the problem is, sometimes computers just have a hiccup where it isn't an actual issue and a restart will make the machine forget there was a problem.
passages: Users may deliberately initiate a reboot. Rationale for such action may include:
  
  BULLET::::- Troubleshooting: Rebooting may be used by users, support staff or system administrators as a technique to work around bugs in software, for example memory leaks or processes that hog resources to the detriment of the overall system, or to terminate malware. While this approach does not address the root cause of the issue, resetting a system back to a good, known state may allow it to be used again for some period until the issue next occurs.
   Usually troubleshooting is applied to something that has suddenly stopped working, since its previously working state forms the expectations about its continued behavior. So the initial focus is often on recent changes to the system or to the environment in which it exists. (For example, a printer that "was working when it was plugged in over there"). However, there is a well known principle that correlation does not imply causality. (For example, the failure of a device shortly after it has been plugged into a different outlet doesn't necessarily mean that the events were related. The failure could have been a matter of coincidence.) Therefore, troubleshooting demands critical thinking rather than magical thinking.
   BULLET::::- Manual, hardware-based: A power switch or reset button can cause the system to reboot. Doing so, however, may cause the loss of all unsaved data.
  
  BULLET::::- Manual, software-based: Computer software and operating system can trigger a reboot as well; more specifically, Microsoft Windows operating systems are outfitted with a restart command that closes open programs and eliminate data loss due to reboot.
  
  BULLET::::- Automated: Software can be scheduled to run at a certain time and date; therefore, it is possible to schedule a reboot.
  
  Section::::Causes.:Power failure.
   The introduction of advanced power management allowed operating systems greater control of hardware power management features. With Advanced Configuration and Power Interface (ACPI), newer operating systems are able to manage different power states and thereby sleep and/or hibernate. While hibernation also involves turning a system off then subsequently back on again, the operating system does not start from scratch, thereby differentiating this process from rebooting.
  
  Section::::Simulated reboot.
   Systems may be configured to reboot automatically after a power failure, or a fatal system error or kernel panic. The method by which this is done varies depending whether the reboot can be handled in software, or must be handled at the firmware or hardware level. Operating systems in the Windows NT family (from Windows NT 3.1 through Windows 7) have an option to modify the behavior of the error handler so that a computer immediately restarts rather than displaying a Blue Screen of Death (BSOD) error message. This option is enabled by default on some editions.
  
  Section::::Hibernation.
   Section::::Terminology.:Hard reboot.
  
  A hard reboot means that the system is not shut down in an orderly manner, skipping file system synchronisation and other activities that would occur on an orderly shutdown. This can be achieved by either applying a reset, by cycling power, by issuing the command in most Unix-like systems, or by triggering a kernel panic.
  
  Section::::Terminology.:Restart.
  
  The term "restart" is used by Microsoft Windows and Linux family of operating systems to denote an operating system-assisted reboot. In a restart, the operating system ensures that all pending I/O operations are gracefully ended before commencing a reboot.
  
  Section::::Causes.
  
  Section::::Causes.:Deliberate.
   This approach may be used in dealing with deadlocks in concurrent programming if they are believed to be very rare and the cost of detection or prevention is high. For example, if each PC deadlocks once per 10 years, the one reboot may be less painful than the restrictions needed to prevent it.
   Unexpected loss of power for any reason (including power outage, power supply failure or depletion of battery on a mobile device) forces the system user to perform a cold boot once the power is restored. Some BIOSes have an option to automatically boot the system after a power failure. An uninterruptible power supply (UPS), backup battery or redundant power supply can prevent such circumstances.
  
  Section::::Causes.:Random reboot.
   Reboot to restore software
  
  ‘Reboot to Restore’ is a system restore technology that enables restoring the user-defined system configuration of a computing device after every restart. The technology helps to maintain systems in their optimum working conditions and is useful especially for multi-user computing environments.
   In a review of the product, Lifehacker wrote, "There's nothing worse than rebooting your computer thinking everything is fine only to find out something's busted and you need to troubleshoot it. It's especially bad if you start having problems after a driver update or a series of Windows updates, and you're stuck trying to figure out which thing caused the problem in the first place. Reboot Restore RX takes the hassle out of it. The app can even restore when Windows won't boot at all."
   BULLET::::- Switching operating systems: On a multi-boot system without a hypervisor, a reboot is required to switch between installed operating systems.
  
  BULLET::::- Offensive: As stated earlier, components lose power during a cold reboot; therefore, components such as RAM that require power lose the data they hold. However, in a cold boot attack, special configurations may allow for part of the system state, like a RAM disk, to be preserved through the reboot.
  
  The means of performing a deliberate reboot also vary and may include:
   Section::::Uses.
  
  Reboot to Restore software solutions were built to simplify the process of maintaining optimal system configuration of devices in a multi-user computing environment such as public libraries, computer labs in educational institutes (such as K-12, colleges, universities) or training centers, public access kiosks, and so on. Due to constant use by multiple people for a wide range of purposes, these devices become susceptible to performance deterioration and malware infiltration.
   Since cold boot attacks target unencrypted random access memory, one solution is to erase sensitive data from memory when it is no longer in use. The "TCG Platform Reset Attack Mitigation Specification", an industry response to this specific attack, forces the BIOS to overwrite memory during POST if the operating system was not shut down cleanly. However, this measure can still be circumvented by removing the memory module from the system and reading it back on another system under the attacker's control that does not support these measures.
   BULLET::::2. Oddly enough, shutting down and booting up again manages to 'fix,' or at least 'mask,' a bug in many computer-based systems; thus "reboot" is the remedy for distressingly many symptoms in a 'fix database.' The reason a reboot often works is that it causes the RAM to be flushed. However, typically the same set of actions are likely to create the same result demonstrating a need to refine the "startup" applications (which launch into memory) or install the latest fix/patch of the offending application.
   As discussed, more transition results in more glitches and hence more power dissipation. To minimize glitch occurrence, switching activity should be minimized. For example, Gray code could be used in counters instead of binary code, since every increment in Gray code only flips one bit. 
  
  Section::::Glitch reduction techniques.:Gate freezing.
   In Windows NT family of operating systems, the blue screen of death (officially known as a stop error and referred to as "bug check" in the Windows software development kit and driver development kit documentation) occurs when the kernel or a driver running in kernel mode encounters an error from which it cannot recover. This is usually caused by an illegal operation being performed. The only safe action the operating system can take in this situation is to restart the computer. As a result, data may be lost, as users are not given an opportunity to save data that has not yet been saved to the hard drive.
   As predicted by Moore's law, the amount of physical memory in all computers has grown almost exponentially, although this is offset to some degree by programs and files themselves becoming larger. In some cases, a computer with virtual memory support where the majority of the loaded data resides on the hard disk may run out of physical memory but not virtual memory, thus causing excessive paging. This condition, known as thrashing, usually renders the computer unusable until some programs are closed or the machine is rebooted. Due to these reasons, an out of memory message is rarely encountered by applications with modern computers.
   Cooling problems are usually obvious upon inspection. A failing motherboard or processor can be identified by swapping-in known-good parts. Memory can be checked by booting to a diagnostic tool, e.g., on Windows with the Windows Memory Diagnostic utility. Non-essential failing i/o controllers and devices can be identified by unplugging them if possible or disabling the devices and drivers to see if the problem disappears. If the failures typically only occur fairly soon after the OS is booted or not at all or not for days, that may be suggestive of a power supply problem, the failure occurring when power demand peaks as the OS wakes up any physical drives and other devices.
   Sometimes operation can be restored for long enough to recover data, perhaps requiring reconstruction techniques such as file carving. Risky techniques are justifiable if the drive is otherwise dead. If a drive is started up once it may continue to run for a shorter or longer time but never start again, so as much data as possible is recovered as soon as the drive starts. A 1990s drive that does not start due to stiction can sometimes be started by tapping it or rotating the body of the drive rapidly by hand.
  
  Section::::See also.
   BULLET::::- Memory of the currently running kernel is overwritten by the new kernel, while the old one is still executing.
  
  BULLET::::- The new kernel will usually expect all hardware devices to be in a well defined state, in which they are after a system reboot because the system firmware resets them to a "sane" state. Bypassing a real reboot may leave devices in an unknown state, and the new kernel will have to recover from that.
   System administrators at corporates deploy reboot to restore solutions to create prestige environments without the need for constant troubleshooting. They use the software to protect the system drive and allocate a separate data partition where user and application data can be stored or redirected.
  
  Section::::Solutions built on Reboot to Restore technology.
  
  Section::::Solutions built on Reboot to Restore technology.:Windows SteadyState.
   Reset (computing)
  
  In a computer or data transmission system, a reset clears any pending errors or events and brings a system to normal condition or an initial state, usually in a controlled manner. It is usually done in response to an error condition when it is impossible or undesirable for a processing activity to proceed and all error recovery mechanisms fail. A computer storage program would normally perform a "reset" if a command times out and error recovery schemes like retry or abort also fail.
   NTF returns are often caused by the following patterns:
  
  BULLET::::- Service technicians using a "shotgun" approach to troubleshooting when they are unable to quickly diagnose a problem or error. Under time pressure to resolve problems quickly, the technician uses multiple replacement parts in hopes that one of them will fix the issue.
  
  BULLET::::- Inability to distinguish hardware problems from software or configuration issues. For example, a device driver problem may mimic a true hardware problem.
  
  BULLET::::- Intermittent problems.
  
  Section::::Impact.
   A common use of the magic SysRq key is to perform a safe reboot of a Linux computer which has otherwise locked up (abbr. REISUB). This can prevent a being required on reboot and gives some programs a chance to save emergency backups of unsaved work. The QWERTY (or AZERTY) mnemonics: "Raising Elephants Is So Utterly Boring", "Reboot Even If System Utterly Broken" or simply the word "BUSIER" read backwards, are often used to remember the following SysRq-keys sequence:
  
  BULLET::::- unaw (take control of keyboard back from X),
  
  BULLET::::- trminate (send to all processes, allowing them to terminate gracefully),
   The traditional init process was originally only responsible for bringing the computer into a normal running state after power-on, or gracefully shutting down services prior to shutdown. As a result, the design is strictly synchronous, blocking future tasks until the current one has completed. Its tasks must also be defined in advance, as they are limited to this prep or cleanup function. This leaves it unable to handle various non-startup-tasks on a modern desktop computer elegantly, including:
  
  BULLET::::- The addition or removal of USB flash drives and other portable storage or network devices while the machine is running
  