explain

[Terry Reedy]

Jeroen Ruigrok van der Werven wrote:
> -On [20090216 11:17], Saeed Iravani (si.422a at yahoo.com) wrote:
>> I download python 2.5.4 and install but I dont know that how perform python?
>> I dont know from which directory perform python?
> 
> It would help if you would clarify which operating system you are using.
> 
> On Unix/Linux systems you make sure to 'rehash' your $PATH or add the
> appropriate directory to the $PATH variable.
> 
> On Windows, you set your environment variable PATH to include the path to
> Python programs (typically something like C:\Python25), which you can find
> under the system control panel.

On windows, that is not necessary for many uses.  Just use the entries 
in the start menu.