in PHP 5.4.5 they have disabled the COM class by default. it wasn't the case with earlier versions. you can enable it by adding following line to your PHP.ini.
Code:
extension=php_com_dotnet.dll
as far as "chcp not found" error is concerned chcp is a system utility available on all windows versions. i am not sure why it's not available on your system although it doesn't matter much.