Question: I have installed Drush-5.4-2012-06-04-Installer-v1.0.18.msi in the location C:\ProgramData\Drush by default. I run the program and moved to drupal working directory.

When I type drush it is showing "drush is not recognized as an internal or external command " error. Do I need to configure anything before run? Please help.

Answer: 
Faced this problem while i was installing drush with composer.

For anyone who have installed drush with composer, if this problem occures, You will have to set PATH variable as follows.

```
F:\Users\{YOUR-USERNAME}\AppData\Roaming\Composer\vendor\drush\drush\;

```

I did this and now my path variables are below.

```
F:\ProgramData\Oracle\Java\javapath;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;F:\Program Files\TortoiseSVN\bin;F:\Program Files\Git\cmd;F:\wamp\bin\php\php5.5.12;F:\ProgramData\ComposerSetup\bin;F:\Users\user\AppData\Roaming\Composer\vendor\drush\drush\;

```

Be careful, Just don't copy paste above variables, you have to append drush path to existing variables.
![enter image description here](https://i.stack.imgur.com/Emvo7.png)
For Drupal, you need to run `composer require drush/drush` command from the root project folder