TB DEV SZ разработка движка

Well i got this error that i dont know how to fix,the problem is that my website doesnt support lithunian letters like ąčęėįšųūž and then they all turn to "?" and i even changed lang_main.php this line:

'language_charset' => /*'iso-8859-1',*/ 'windows-1257',

Then all russian letters become lithunian but when i want to write news my letters turn to "?" the same is with categorys
please help me