gitignore - Ignore file with GitHub on windows -

i use github on windows, cloned wordpress project locally. @ root, project contains file .gitignore lines :

*.log wp-config.php 

so should not have wp-config.php file in root, wp-config.php present locally.

if right-click > "ignores file" on client: new line added file .gitignore file not ignored.

do know why ?

thank !

one possible explanation seeing file wp-config.php being tracked git. doing git status tell happening. if file being tracked must following command in addition adding .gitignore:

git rm --cached wp-config.php