not right, left in that orange column
Please take a look into your C:\xampp\htdocs\xampp\lang.tmp
If the file doesn't exist, please create one.
If it's content is not just en
for english, please change it to en
The other way would be to first go to the main page http://localhost/xampp/
, you should have been redirectled to the splash site http://localhost/xampp/splash.php
where you can choose your language.
If that doesn't work too, then you should maybe reinstall your whole XAMPP.