//=== display assoication
> assoc .py
.py=Python.File
//=== set association
>assoc .pys=pysFile
//=== remove association
> assoc .pys=
//=== ftype (file type)
> ftype |findstr Python
Python.CompiledFile="...\Python27\python.exe" "%1" %*
Python.File="...\Python27\python.exe" "%1" %*
Python.NoConFile="...\Python27\pythonw.exe" "%1" %*
//=== where
> where assoc
??? could not find files for the given patterns
> where demo.bat
//=== pathExt
> echo %pathExt%
//=== http://pcsupport.about.com/od/fixtheproblem/ht/default-program-windows-7.htm
Control Panel\All Control Panel Items\Default Programs\Set Associations
Control Panel --> Default Programs --> Associate a file type or protocol with a specific program
