Virus : One line code to hang your friend's PC

1) Open any text editor (Notepad) and Type

%0|%0 

​​2) Save it as a batch file that is file extension must be .bat .

​​3) This step is optional to check what is going to happen. Open task manager by pressing Ctrl + Alt + Del and click on performance tab to view the changes those are going to happen.

4) Run the batch file.

​5) Within the few seconds performance of your machine will be 100% memory will be full and within a minute your machine will be hanged.

Explanation : 

In Windows, “%0” is the name of the currently executing Batch File. By executing %0|%0, we are recursively calling the Batch File, thereby creating many processes and utilizing CPU resources up to a point where CPU cannot offer more resources to the processes which will be created(forked) after a certain amount of time.