Error 500 in admin after trying to install google checkout mod

Hello,

I just tried to install google checkout mod, thought i followed everything to the letter, but when i try to go into the admin section now i get a HTTP 500 error screen.

The php errors i get are:
[11-Sep-2008 15:51:17] PHP Warning: require(includes/languages/english.php) [<a href='function.require'>function.require</a>]: failed to open stream: No such file or directory in C:\xampp\htdocs\store\boss\includes\init_includes\init_languages.php on line 31

[11-Sep-2008 15:51:17] PHP Fatal error: require() [<a href='function.require'>function.require</a>]: Failed opening required 'includes/languages/english.php' (include_path='.;C:\xampp\php\pear') in C:\xampp\htdocs\store\boss\includes\init_includes\init_languages.php on line 31

I have the includes/languages/english.php, so unsure why it isn't working? any help or ideas of what to do next would be great :)

p.s Trying to install on my local website before uploading on my real one

Thanks