You have to give us more information than that. We don't know the operating system or anything. Do you mean that you don't have the ability to use the English alphabet or what?

If you are using XP you can set the default language by going to the Control Panel, Choose Category View and then choose
Date, Time, Language and Regional Options.
Then you can pick an option. Choose Add Other Languages.
When that opens you can set your Default Language right there. Click and Regional Language Options opens. Click the Language Tab. When that opens Click Details. There you can set the Default Language.

See this link for full instructions:
http://www.microsoft.com/windowsxp/using/setup/winxp/yourlanguage.mspx