April Fool’s Day tech pranks and geeky jokes to play on your friends

Really confuse your friend by taking a screenshot of their desktop, and setting that image as their wallpaper. The most evil among you can then remove all their documents and folders from their desktop  (hide them in a separate folder) and watch as they click on folders and documents and complain that they are not opening. Hilarious! 

How to take a screen shot:There are lots of ways to take a screen shot on a Mac, as we discuss in this article, however, the best way to grab a grab of their screen is to select shift-cmd-3. If you are going to use this as wallpaper, drop the image into the Pictures folder on their Mac.

How to change wallpaper: The quickest way is to right-click (ctrl-click) on the desktop, choose: Change Desktop Background, then go to Folders > Pictures and select the wallpaper of deception.

We’re sure your friend will love to see your face staring back at them when they turn on their Mac. Rather than the obvious wallpaper switcheroo, why not change each of the icons on their desktop to your smiling face. For additional evil points, find the most embarrassing photos you have of them and scatter around their desktop. They will love you for it.

How to change an icon: Find that gorgeous photo of yourself, or a not so gorgeous photo of your friend. Open it and cmd-c to copy it to the clipboard. Now right click on an icon you wish to change, select Get Info, and now select the small folder icon beside the name of the file or folder. Cmd-v to paste your smiling face in to place and you are good to go. Of course if you plaster your mug all over their desktop they will know it was you, so maybe you’ll want to dig out the most embarrassing photos of the – there are sure to be plenty on Facebook.

Read: How to customise your Mac desktop

A really quick way to completely change the look and feel of your nemesis’s Mac is to pop over to Accessibility (in System Preferences). Select Display and then choose Invert Colours.

Now white will be black and black will be white and they won’t know whether they are coming or going. You can also take the colour right out of their lives by selecting Use Grayscale.

While in Accessibility why not mess around with their cursor as well as their mind. Make the cursor large by sliding the guide.

Go to System Preferences > Keyboard and select Text. Here you can set things up so that certain words will be automatically replaced with a different word. Click on the + and enter a word you want to automatically change every time they type it. Pick your alternative word. Now watch as they try and type April and every time their Mac types Fool. (This will only work in Apple apps, such as Safari, Mail and Text Edit.) Mwahahaha.

Change the language of your friend’s Mac. Visit System Preferences > Language & Region. Now select + and choose your preferred language.

It might take a restart to get the new language to appear, but when it does, it’ll be funny, ya!

Even more hilarious, go to System Preferences > Keyboard > Input Sources. Select + and choose a new keyboard. Now select a keyboard of your choice. Perhaps French, or for the really creative, perhaps you could hand them some Chinese characters.

Now click on the flag in the menu at the top of the screen, and switch it to an alternative flag – now the keyboard associated with that country will be in use. The French keyboqrd is pqrticulqrly hillqrious to use qs it only szitches so,e chqrqcters.

Read: Mac keyboard shortcuts you should know

You can make them want to have a lie-down by changing the text direction in a Word document.

Open a Word document they are working on, go to: Format > Text Direction and choose which direction you think the text should follow. 

Open Safari on their Mac. Go to Preferences and enter an embarrassing URL as their Home Page, preferably something really loud.

Now go back to System Preferences > Users & Groups, select their user profile and then Login Items. Now click on + and add Safari to their Login Items. You’ll find it in Applications.

Now when they restart their Mac it will greet them with the Safari web page you selected. Even better if it is a YouTube video staring them!

Don’t forget to switch their screensaver to something terrifying. Start by grabbing a folder of images of them. Then right-click (or ctrl-click) on the desktop, select Desktop and Screensaver and go to Screen Saver. Pick one of the slideshows – we like Floating, and then choose Source.

Select Choose Folder and find the folder of images you prepared earlier. We made a folder of cute kittie pictures that we plan to continue to use, because, look…

Read our complete guide to System Preferences for more ways to annoy your friends.