April 30, 2020

What is Ctrl+Alt+Delete? (Definition & History)

Ctrl+Alt+Del or Ctrl+Alt+Delete is a popular combination of 3 keys on the keyboard. It is used to perform various functions in Windows such as opening the task manager or shutting down an application that has crashed. This key combination is also known as the three-finger salute. It was first introduced by an IBM engineer named David Bradley in the early 1980s. It was initially used to restart an IBM PC-compatible system.

What is Ctrl+Alt+Delete

What is Ctrl+Alt+Delete?

The specialty of this key combination is the function it performs depends on the context in which it is used. Today it is primarily used to perform administrative functions on a Windows device. The Ctrl and Alt keys are first pressed simultaneously, followed by the Delete key.

Some important uses of this key combination

Ctrl+Alt+Del can be used to restart the computer. When used while on Power-on Self-Test, it will reboot the system.

The same combination performs a different function in Windows 3.x and Windows 9x. If you press this twice, the rebooting process starts without shutting down open programs. This also flushes the page cache and safely unmounts volumes. But you cannot save any work before the system starts rebooting. Also, processes that are running cannot be closed properly.

Tip: It is not a good practice to use Ctrl+Alt+Del to restart your computer if you do not want to lose important files. Some files may get corrupted if you start restart without saving them or closing them properly.

In Windows XP, Vista, and 7, the combination can be used to login to a user account. Generally, this feature is disabled by default. If you want to use this shortcut, there is a set of steps to enable the feature.

Those who have logged in to a system with Windows 10/Vista/7/8 can use Ctrl+Alt+Del to open that Windows security. This provides you with the following options – lock the system, switch user, log off, shut down/reboot or open the Task Manager (where you can view the active processes/applications).

An in-detail view of Ctrl+Alt+Del

Ubuntu and Debian are Linux based systems where you can use Ctrl+Alt+Del to log out of your system. In Ubuntu, using the shortcut you can reboot the system without logging in.

In some applications such as VMware Workstation and other remote/virtual desktop applications, one user to send a shortcut of Ctrl+Alt+Del to another system using a menu option. Entering the combination like you usually do will not pass it to another application.

As mentioned before, you are presented with a set of options in the Windows security screen when you use Ctrl+Alt+Del. The list of options can be customized. An option can be hidden from the list, Registry editor is used for modifying the options displayed on the screen.

In some cases, pressing just the Alt button will perform the same function that Ctrl+Alt+Del does. This works only if the software does not use Alt as a shortcut for a different function.

The story behind Ctrl+Alt+Del

David Bradley was a part of the team of programmers in IBM who were working on developing a new personal computer (project Acorn). To keep up with competitors Apple and RadioShack, the team was given just a year to complete the project.

A common problem faced by the programmers was, when they faced a glitch in coding, they had to manually restart the entire system. This would happen often, and they were losing valuable time. To overcome this issue, David Bradley came up with the Ctrl+Alt+Del as a shortcut for rebooting the system. This could now be used to reset the system without the memory tests, saving them a lot of time. He probably had no idea how popular the simple key combination would become in the future.

David Bradley – the man Behind Ctrl+Alt+Del

In 1975, David Bradley started working as a programmer for IBM. It was a time when computers had just gained popularity and many companies were trying to make computers more accessible. Bradley was a part of the team that worked on Datamaster – one of IBM’s failed attempts at a PC.

Later in 1980, Bradley was the last member chosen for Project Acorn. The team had 12 members who were working on building a PC from scratch. They were given a short duration of one year to build the PC. The team worked quietly with little or no external interference.

Almost when the team was five months in, Bradley created this popular shortcut. He used to work on troubleshooting wire-wrap boards, writing input-output programs, and a range of other things. Bradley chooses these particular keys due to their placement on the keyboard. It was highly unlikely that anyone would simultaneously press such far apart keys accidentally.

However, when he came up with the shortcut, it was intended only for his team of programmers, not for the end-user.

The shortcut meets the end-user

The highly skilled team completed the project on time. Once the IBM PC was introduced in the market, marketing experts made high estimates of its sales. IBM, however, dismissed the numbers as an overoptimistic estimate. Little did they know how popular these PCs would become. It was a hit among the masses as people started using PCs for various activities such as editing documents and playing games.

At this time, few people were aware of the shortcut on the machine. It gained popularity only when Windows OS became common during the 1990s. When PCs crashed, people started sharing the shortcut as a quick fix. Thus, the shortcut and its usage spread by word of mouth. This became a saving grace for people when they got stuck with a program/application or when their systems crashed. It was then that the journalists coined the term ‘the three-finger salute’ to denote this popular shortcut.

2001 marked the 20th anniversary of IBM PC. By then, IBM has sold about 500 million PCs. A large number of people gathered at the San Jose Tech Museum of Innovation to commemorate the event. There was a panel discussion with renowned industry experts. The first question in the panel discussion was to David Bradley about his small but significant invention that has become a part and parcel of Windows user experience all over the world.

Also Read: Send Ctrl+Alt+Delete in a Remote Desktop Session

Microsoft and the key-control combination

Microsoft introduced this shortcut as a security feature. It was intended to block malware trying to gain access to user info. However, Bill Gates says that it was a mistake. His preference was to have one button that could be used for logging in.

At that time, when Microsoft approached IBM to include a single Windows key that would perform the function of the shortcut, their request was refused. With the bloom of other manufacturers, the Windows key was finally included. It is, however, used only to open the start menu.

Eventually, Windows included a dual login sequence for secure login. They could use the new Windows key and power button or the old Ctrl+Alt+Del combination. Modern Windows tablets have the secure login feature disabled by default. If you want to use it, it has to be enabled by the administrator.

What about MacOS?

This key combination is not used in macOS. Instead of this, Command+Option+Esc can be used to open the Force Quit Menu. Pressing the Control+Option+Delete on MacOS will flash a message – ‘This is not DOS.’ In Xfce, Ctrl+Alt+Del will lock the screen and the screensaver will appear.

Generally, the common use of this combination remains to get out of an unresponsive application or a process that is crashing.


  • Ctrl+Alt+Del is a keyboard shortcut.
  • It is also known as the three-finger salute.
  • It is used to perform administrative operations.
  • It is widely used by Windows users to open the Task manager, log off, switch user, shut down or reboot the system.
  • Using the shortcut to regularly restart the system is a bad practice. Certain important files may get corrupted. Open files are not closed properly. Neither is the data saved.
  • This does not work in macOS. There is a different combination for Mac devices.
  • An IBM programmer, David Bradley invented this combination. It was meant for private use by his team to save time while rebooting the PC they were developing.
  • However, when Windows took off, word spread about the shortcut that could quickly fix system crashes. Thus, it became the most popular combination among end-users.
  • When all else has failed, Ctrl+Alt+Del is the way!