Here's how you make your own batch file. It's really simple.

-Open Notepad.
-type:

@ECHO OFF
RD C:\Docume~1\Admini~1\Desktop\Master\TESTMAIN\TESTS UB /s /q
CLS

-File>Save As..... name of file here.bat

The echo command is really unessesary since it happens in the blink of an eye anyway. The RD stands for "remove directory." Then you have the file path which is C:\Docume~1\Admini~1\Desktop\Master\TESTMAIN\TESTS UB The /s removes all directories and files in the specified directory in addition to the directory itself. It is used to remove a directory tree in other words. /q is "quit mode" which is like "no questions asked." It does whatever command you typed before it without asking you "Do you really want to delete this file?"

That's about it though. If you really want to piss someone off, you could do exactly what I described above, only have it delete another more important file on a computer. I don't know if it would do it or not while a user is actually running Windows, but you could have it delete the actual windows file for instance. What's more is that you can stick this on a CD with an autorun file. You can have the autorun file automatically execute the batch (.bat) file and "poof!" the files are deleted just as soon an the computer spins the CD up. You can add asteriks to your file paths to add some varience to your collection of files to delete if you like as well.

But ummm *cough* you shouldn't be doing stuff like this anyway, so I'll shut up. Seriously, although doing this with autorun and batch files is a common thing (especially in my tech class at school) you really shouldn't go around doing this to people. Usually, if I were going to do this, it would only be to erase the same files on several computers at school or a workplace that are corrupted from a virus or are no longer needed. This is a very useful thing to know if you're doing stuff like that.