Question

A couple of months ago, I returned from lunch to find that typing any key launched a random application. As I always lock my machine before walking away from it, my first thought was that a co-worker was playing a practical joke on me. As it turned out, the cause was random computer wonkiness. But just in case there's a need :), what's your favorite harmless computer practical joke? For example, would you alter host file entries to direct google.com to a random site or would you put tape over the optical sensor of a co-worker’s mouse?

Answer 1

At work we once put on an unattended computer:

Outlook rules that went something like this: when receive email with subject 'duh':

1. Delete email
2. Launch the calculator
3. Play a Homer Simpson audio click 'lets do some calculating'

It caused a lot of laughs during team meetings.

Answer 2

My all time favourite was a small application I wrote and installed on a colleagues computer.

It silently ran in the background and chimed every hour by opening and closing the CD tray and playing a "cuckoo" sound.

Effectively turning their PC into a cuckoo clock.

Answer 3

Taking a screenshot of the desktop and hiding the icons.

Answer 4

#define if while

Answer 5

My coworker tells a story of a long term practical joke on a non-technical user.

Every day, at the end of the day, he'd pick up the mouse and squeeze the mouse cord following it up back to the computer when she was watching - but not when anyone else was around.

Eventually her curiosity got the better of her, and she asked about his habit. He explained that he was pushing the electrons back up into the computer so the mouse wouldn't get bogged down with extra electrons every day and eventually get slower and slower.

She soon took up the habit, and hilarity ensued when her boss asked her about it.

Answer 6

This guy was tired of his neighbours using his wifi-network, so he made a setup that flipped all images upside down when they browsed the net:

Classy and harmless.

Answer 7

My wife hogs our macbook all the time, so I set up a static IP on our router for it which allows me to SSH in from work (or anywhere else) and use the say command to have random messages read out. She still doesn't know it's me - it's getting hard to keep a straight face when she complains that the macbook announced that "the radish only floats on one side" in a sing-along jaunty voice this afternoon.

I also used to enjoy SSHing onto newbie unix users boxes and randomly ejecting the CDs they were listening to.

Answer 8

Adding the words "teh", "adn", and "fro" to someone's Word dictionary.

Answer 9

A coworker of mine once left her computer unlocked when she went home for the day.

We created an email in Outlook, addressed it to a boss she couldn't stand, wrote a love letter to him, then used Paint to make a desktop-sized image with the email positioned to the right of where her desktop icons were. Then we set it as the background and locked her computer.

So the next day she sees this loaded gun of an email, can't figure out why she can't close it, and is freaked out that she might click it wrong and send it.

Bonus hilarity points ensued when she rebooted in panic and it came back.

(this was someone who was a really good friend of ours so we all had a good laugh over it - it wasn't like we randomly picked someone)

Answer 10

If you're sitting near them (opposite or along side), plug a USB mouse into their PC and every now and again move their mouse pointer. The two mice share the pointer, so done well you can fight their attempts to move the pointer left/right by moving your mouse in the other direction.

You can do the same with a second keyboard too!

Answer 11

Prank 1

At my old job my Co-Worker's son pranked me by sending me a link that looked legit but when I opened it, the page loaded a small flash app that played "I am looking at Porn!" really loudly. A few people in my office heard my computer and laughed. So I copied the swf file and created a new page with javascript that would spawn 10 new windows then each of those would spawn 10 new windows and so on -- each one had the "I am looking at Porn!" swf file that loaded. I emailed him the link. If I remember right, I put it somewhere on our company site so it looked legit. About 15 minutes later I got a reply with "Nice."

Apparently he was in a computer class in High School and wasn't supposed to be surfing or checking email. He said it kept playing the sound really loudly before locking up his computer and bringing the teacher over to his desk.

---

Prank 2

Same old job. One morning before anyone got in, I switched the M and the N keys on a co-worker's keyboard who I knew was a hunt and peck typer. He called me over later that day to look at his computer because, "the keyboard typed the wrong letter" when he typed. I sat there a minute, tried it in Word and Notepad then went into control panel and acted like I was checking on things. Finally, I pulled out my car keys popped the letters off the keyboard and switched them back (to their correct original positions). I looked at him and said, "Use it like this, you will get used to it" and I walked away. He threw a fit about that not being a valid fix. He was so mad -- it was awesome.

Answer 12

I remember installing a Blue Screen screen saver on a friend's computer at the time he was writing his Master's thesis. Worked great.

Answer 13

This works on any militant MAC user

1. Ask to borrow their MAC
2. Install Microsoft Terminal Server Client for MAC (Free DL)
3. RDP into a Windows machine using full screen mode
4. Give the MAC back to the militant MAC head and say, "Here - I fixed your MAC"

Answer 14

I have to admit, this is one of my dad's - and I'm a little rusty on details.

On a colleague's Unix machine, he injected some code into something related to the keyboard - a driver, or some handler for the input somehow. Basically, any time this person typed beyond about 45 words per minute, subtle typos kept being added; only keys added would be close to the key being hit. A would become an S or a Q or a Z, a Y may become a U.

The cruel part was that it would only happen if you typed quickly - if you backed up and typed it again slowly it would work perfectly. The faster one typed, the faster the errors came.

Answer 15

Only works on a Unix system, but editing a .profile (or .cshrc or other similar file):

echo 'Deleting user account'
echo 'rm -rf ~/.'
sleep 1800

Answer 16

Clippy is pretty hilarious.

Answer 17

Back in the days of AOL, I used to change people's "Welcome!" .wav file to the "Goodbye!" .wav file. So, people would sit there listening to the modem dialing, trying to connect, retrying, retrying x 50, then get excited hearing it connect. Then there would be the conclusive "Ding! Ding!" and "Goodbye!", usually followed by expletives, then confusion. The range of emotional expressions witnessed within those few seconds was incredible.

Answer 18

I always like putting the following in someone's .profile:

echo sleep 1 >> ~/.profile

Answer 19

• Move the Dock or taskbar away from the bottom of the screen and set it to autohide.
• Turn on voiceover and set it to maximum verbosity.
• Use cron jobs along with the say to make the computer sing songs.
• Set up a cron job to alter the hosts file and the change it back 10 minutes later.
• Create a cron job to periodically call touch to create blank files on somebody's desktop or home directory
• Get a cheap pair of headphones, cut off the cable and plug it into a headphone jack on the back of the computer. This can go unnoticed for an astoundingly long time.
• Turn off wireless keyboards and mice. For bonus points swap them with the ones on other keyboards.
• Hold down windows-e for a few seconds
• ctrl-option-cmd-8
• turn on sticky keys
• periodically press ctrl-option-cmd-.
• add lots of files to the dock
• Insert CDs upside-down
• run vim no really... it is very hard to quit the program if you don't know how
• set word to auto correct I to A

Bury these in a C program

• #define cout cou
• #define true false or #define false true
• #define int float or #define float int

• #define continue break

• Change the switch from more magic to magic

Answer 20

In style.css:

if date.month() == 4 and date.day() == 1 and random(1000) == 0:
    print 'body { direction: rtl; }'

Answer 21

We had a consultant who was pretty unpleasant and spent all day playing Solitaire.

I replaced Solitaire with a batch file that printed a message:

The system has detected unauthorized use of "Solitaire".
Please contact the System Administrator immediately to re-enable Solitaire.

Of course, he'd never go to Sys Admin so he'd never get to play Solitaire.

Answer 22

This is will reveal who did this prank (me) to any of my coworkers who find this post, but...

There is a Perl script out there that lets you change the READY... message on most HP laser printers to any message you would like. It goes back to READY... when the printer is rebooted or reset, so no harm done. For about two years, I've randomly been changing the READY message on our bay's shared printer. Sometimes to something topical, like "BRRR. TURN DOWN THE AC." or "LIMIT PRINTING. I'M HUNGOVER", sometimes personal ("HELLO DAVE!"), sometimes misleading ("PLEASE INSERT COIN"). Everyone would talk about them, but no one reported the printer as broken. At the time.

My favorites, though, were the obscure and surreal - mostly riffs on Discworld. I set it once before going to lunch and when I came back to the office, I was standing behind two guys from the IT support group who were trying to figure out why someone would report that the laser printer was displaying:

OUT OF CHEESE ERROR! MR. JELLY! MR. JELLY!

I almost got the coworker who reported the problem in trouble because someone had rebooted the printer before the IT guys got there and they thought he was pulling the prank because there was no way the printer could have an out of cheese error and they had searched the HP support site and couldn't find any reference to Mr. Jelly.

Answer 23

Years ago a co-worker at a start-up told the CEO he had an idea for how to implement a very robust speech-recognition engine and had spent the weekend building a prototype. With the CEO watching, he sat down and dictated commands and text to enter. He then invited the CEO to try it (no training required). It worked flawlessly (though sometimes there was a slight delay). We could see the dollar signs spinning in the CEO's eyes.

Then the co-worker revealed that someone else across the office within earshot had been controlling the computer remotely (using a remote AppleScript--this was before VNC).

Answer 24

Windows XP Users:

Find a target.

Wait until they leave PC unattended.

Press SHIFT+ALT+PRINTSCREEN.

High contrast mode is the activated and the whole system should go into what i like to call "Retro Mode".

Retreat and enjoy.

PS. To deactivate repeat the original key combo :D

(Its also funny if you just walk up and press the key combo specified when they are at the station, then they beg you to turn it back and everyone gets a cheap laugh!)

Answer 25

printf("Segmentation fault");

Answer 26

A guy at the help desk kept getting called by the woman in the cube next to me for the dumbest of reasons. Finally, he had enough and played this prank on her:

He popped the U and the I keys off her keyboard and swapped their locations. She finally had to call into the help desk and reported that her keyboard was malfunctioning by typing U when she clicked I and vise versa.

Funniest part? She said it only happened 60% of the time (probably when she was looking at the keyboard).

Answer 27

The user's computer has to have IIS or Apache installed on it for this to work.

1. Take a screenshot of Google.com.
2. Copy the center of the image containing the logo, search box, and search button into the center of a blank html page.
3. Save that html page to the webroot on the user's computer. And make sure it is the default page served up by IIS or Apache.
4. Alter the user's host file (/windows/system32/drivers/etc). Add a new line 127.0.0.1 google.com
5. Enjoy watching the person freak out as 'the google' is broken.

Answer 28

Modify an in-house piece of software with a timer that moves the main window to the left one pixel every 15 seconds or so when the computer is idle...

Answer 29

Well, back in the day, I removed the ball from a friends mouse. Can't really do that one anymore...

A piece of tape over the optical sensor should do about as well as removing the mouse ball.

Answer 30

Set different color tones on the monitor. Usually doesn't get noticed quickly, and gives an eerie "somethings wrong but I can't place my finger on it"-feeling.

-"Does my screen look brown-ish to you?"

-"Nope, must be your eyes playing a trick"