I will confirm once I did the following it worked for me... Thank you for your assistance...
1. Before installation Prestashop, I tried to download 'en.gzip' file from
'http://www.prestashop.com/en/translations' and copied it to folder
..\prestashop_1.5.4.0\prestashop\translations (Another languages might do like this)
2. Open file name 'language.xml' in folder ..\prestashop\install\langs\en for edit
and go to tag line '<language_code>' and change from
<language_code>en-us</language_code> to
<language_code>en</language_code> and save then close
CRAD