Incorrect

If the victim uses Microsoft Word, go into the victim's computer and change the auto-correct feature so it misspells common words. Just open Word, choose “AutoCorrect Options” from the Tools menu, and have it replace common words like “the” and “and” with wacky words like “eggplant” or “Uranus.” Be creative.

Dark Side

On most computer monitors, if you turn the brightness control all the way up and the contrast all the way down, the screen will appear to be blank. Do this to your victim and they will drive themselves crazy trying to “fix” their “broken” monitor.

Lost Buttons

Go to Start->Settings->Control Panel and find the option for your Mouse. On the Buttons tab, change the buttons configuration to switch the primary and secondary buttons of the mouse. Now when the victim clicks with the mouse, nothing will work as expected.

Hurry Up

Change the cursor on the victim's computer. Go to Start->Settings->Control Panel->Mouse, and select the “Pointers” tab. Then change the cursor to the hourglass image. Now the victim will think their computer is stuck on a task endlessly.

Away From Home

Change the victim's homepage to something unexpected. Open their browser and choose Tools->Options and enter the URL for a new page.