Some of Microsoft's early products included hidden Easter Eggs. Microsoft formally stopped including Easter Eggs in its programs as part of its Trustworthy Computing Initiative in 2002.^[1]

Windows 1.0, 2.0 and 2.1 all include an Easter egg, which features a window that shows a list of people who worked on the software along with a "Congrats!" button. Double clicking the list box further changes the background of the window to tiled smiley faces. The instructions for invoking the Easter egg vary depending on the version:^{[citation needed]}

• 1.xx: Press Alt+⇧ Shift+Esc+↵ Enter.
• 1.01 and later: Hold Alt then Esc, release Alt then Esc, press Esc twice then press ← Backspace.
• 2.0 and later: Press F1, F5, F9, F4 and ← Backspace in rapid succession.

Windows 3.0 has a developer credits page which may be accessed by setting the focus to the desktop (by minimizing all windows and clicking on an open area of the desktop) then typing win30 followed by F3 and ← Backspace in quick succession. This causes the developer credits to appear on the desktop in the form of the email names of the crew.^[2]

Windows 3.1 has two visible Easter eggs, both of which reference the Microsoft Bear, which was the mascot of the Windows 3.1 development team.^[3] One was the developer credits, where the Bear, along with Bill Gates, Steve Ballmer, and Brad Silverberg, present the email aliases of the Windows 3.1 developers. bradsi, being in charge of Windows production, is listed first; the three other presenters, billg, steveb, and t-bear, appear together in "Special Thanks", the last section of the list.^[4] The other one was a reference to a fictitious file named BEAR.EXE in the properties window for the MS-DOS Prompt.^[5] Internally, there was another egg, where several internal system functions (although having meaningful internal names) were exported from user.exe as BEARNNN (where NNN is the ordinal number of the function) in his honor and to discourage their use by third-party software developers. The user can also find the easter egg by opening the About Program Manager, holding down Ctrl, Alt and ⇧ Shift, double click one colored square of the Microsoft Windows logo, and then close the window. Open it again and do so with a different square (with the keys still pressed down). Keep repeating this until the Microsoft Bear appears in the window, as seen to the right.^{[citation needed]}

Windows 95 has an animated presentation of its developers, complete with music. This page is accessed by renaming a folder on the desktop to "and now, the moment you've all been waiting for", then "we proudly present for your viewing pleasure", and finally "The Microsoft Windows 95 Product Team!". Additionally, a dialog with credits can be invoked from the Windows Help application.^[6][7]

During the development of Windows 95, the shell developers had several stuffed animals as mascots. In addition to the Microsoft Bear, there were two bunnies as well - the smaller 16-bit Bunny and the larger 32-bit Bunny. The bunnies' names referred to the fact that Windows 95 was the transitional OS.^[3] The Microsoft Bunny has an exported function named after him, BUNNY_351 in krnl386.exe.^[8] Also, the Bunny is the icon for the Microsoft Party Line (rumor.exe) in some pre-release versions of Windows 95. In the internet mail app, there is a hidden credits list that can be accessed by clicking Help, About, comctl32.dll, and typing MORTIMER.^[9]

Windows 98 has a credits screen Easter egg, which can be triggered by invoking weldata.exe with the argument "You_are_a_real_rascal" in the command line or a shortcut (.lnk file), or by clicking and dragging between the locations of Memphis, Egypt; Memphis, Tennessee; and Redmond, Washington on the Time Zone map. (This easter egg is a reference to "Memphis" being the development codename of Windows 98.)^[10]. Also credits are contained in registration wizard, holding down the Ctrl+⇧ Shift keys and right-click on the image to the left.^[11]

A drawing of the Microsoft Bear was used as the icon for the SETDEBUG.EXE and JDBGMGR.EXE system files. The odd icon gave credibility to the jdbgmgr.exe virus hoax, which claimed that the files were part of a computer virus.^[12] See SULFNBK.EXE for a similar hoax.

The Pipes screensaver in Windows 95 (OSR2 onwards), 98, ME, NT 4.0 and 2000 will occasionally insert a Utah teapot as a joint between pipes when the screensaver is configured to draw multiple, traditional-style pipes with mixed joint types and a solid texture.^[13] Windows 2000 and Windows XP have an undocumented texture in the Pipes screensaver (sspipes.scr) that makes the pipes red and white, similar to candy canes.^[14]

An Easter egg that displays the names of all the volcanoes in the United States can be found in the 3D Text screensaver on all versions of Microsoft Windows prior to Windows XP by setting the text to display to "Volcano".^[15] In Windows NT 3.5, setting the text to "I love NT" shows the names of the developers. "Rock" and "Beer" lists bands and breweries, respectively.^[16] In Windows NT 4.0, the phrase to view the developer credits was changed to "not evil". Setting the text to "I love NT" will instead simply display "good?".^[17]

Three images are embedded in the surface of Windows Vista's installation DVD. One of the images shows the faces of the members of Microsoft's anti-piracy team who worked on the hologram.^[18]

In Windows 10 build 16232, the "Windows is checking for a solution to solve the problem..." dialog that appears when a program crashes is replaced with "Windows is opening a portal to another dimension..."^[19]

These features below were discontinued because Cortana is no longer available.

• When asked if she likes Clippy, Cortana would answer "Definitely! He taught me how important it is to listen." or "What's not to like? That guy took a heck of a beating and he's still smiling." Her avatar then occasionally turns into a two-dimensional Metro-style Clippit for several seconds^[34] Similarly, you can ask "Do you know Clippy?" or "Where is Clippy?", and a response will also be given.
• Asking Cortana "What does the fox say?" would make her respond with "Ring-ding-ding-ding-dingeringeding", a reference to the 2013 song The Fox^[35]
• Cortana had several Easter Eggs referencing the Halo franchise including, but not limited to, the questions, "What is Halo?", "Tell me about Halo", "Do you love Master Chief?" and "How is Master Chief?"^[35]
• Saying, "May the force be with you" to Cortana would make her reply "My ally is the force, and a powerful ally it is", a reference to the Star Wars franchise.^{[citation needed]}
• Asking, "What is the airspeed velocity of an unladen swallow?" would make Cortana respond "What do you mean? An African or European swallow?", a reference to Monty Python.^[36]
• Saying, "Up up down down left right left right B A start" to Cortana would make her say, "That it is the Konami Code, not the Cortana Code."^{[citation needed]}
• Asking Cortana, "Who lives in a pineapple under the sea?", would make her respond with "SpongeBob SquarePants!", a reference to the theme song of the 1999 animated series SpongeBob SquarePants.^{[citation needed]}
• Asking Cortana to do a barrel roll would cause her to respond with "How about a sausage roll?", "How about a swiss roll?", or "How about a spicy tuna roll?".

• In one of the missions of Microsoft Flight Simulator X, called "Secret Shuttle", the player's call sign is changed mid-flight to a one that starts with "Longhorn". After landing at Area 51, a request from another aircraft for departure clearance, whose call sign starts with "Vista" can be heard over the radio. "Longhorn" was the development codename for the then-upcoming Windows Vista operating system, which was released worldwide in 2007. The game was released in 2006.^{[citation needed]}
• The Xbox console contains developer credits in the dashboard. Inserting an audio CD and ripping it with the name "<<Eggsßox>>" would trigger it.^[37]
• The Xbox games console contains hidden, modified sounds of the Apollo space missions of which are conversations that are currently in the public domain. The sounds would only play when the console is idle on the Xbox dashboard for a long period of time.^[38]
• A super deformed cartoon depiction of Halo protagonist Master Chief can be seen inside the Xbox One S's plastic casing^[39] and on the Xbox One X's motherboard.^[40]

• Typing WAIT6502,1 into a Commodore PET with BASIC V2 (1979) would result in "MICROSOFT!" printed on the top left of the screen, partly overwriting the first line "### COMMODORE BASIC ###".^[41]
• In Microsoft QBasic, there is an Easter Egg where the developers credits can be seen at start up, printed in colorful text, flying in one letter at a time from every corner.^[42]
• Acid1 is included as an offline Easter Egg, accessible by typing 'about:tasman', in Internet Explorer 5 for Mac OS with the text replaced by the names of the developers.^[43]
• Typing edge://surf into the address bar in Microsoft Edge versions higher than 83 will allow users to play Surf, a game where the player controls a surfer who must collect powerups and run from a Kraken. This game bears resemblance to SkiFree, another Microsoft-developed game, and has been compared to Google Chrome's Dinosaur Game.^[44 The game contains some easter eggs of its own, such as a cameo during the "Time Trial" mode and a hidden costume if the is entered on the surfer select screen.

• List of Google Easter eggs