Language setting problem...

I am using Oracle8i 8.1.7 for Win2000. And now cannot handle Chinese character
inside Oracle. All the Chinese character becomes question marks "????". How to
fix the problem?

I have:
- Win2000 in English version.

• Create database using ZHT16BIG5 as its code setting. (choose it from Custom Install page)
• NLS_LANG environment already set as "TRADITIONAL CHINESE_TAIWAN.ZHT16BIG5" on both client side and server side(actually both client & server are on the same machine at the moment). I have verified by SET command, it's fine.
• Added: NLS_LANG = "TRADITIONAL CHINESE" NLS_TERRITORY = "TAIWAN" into "init.ora" before starting database.
• Examined the database by: "select * from NLS_DATABASE_PARAMETERS" and find that two parameters are still leaving English setting: NLS_LANGUAGE = AMERICAN NLS_TERRITORY = AMERICA (I wonder why it cannot affect by parameters of init.ora and don't know how to change it) two parameters value are correct: NLS_CHARACTERSET = ZHT16BIG5 NLS_NCHAR_CHARACTERSET = ZHT16BIG5
• Examined the database by: "show parameters nls" So stranger, I find that: NLS_LANGUAGE = "TRADITIONAL CHINESE" NLS_TERRITORY = "TAIWAN"
• Tried to connect by Oracle client from NT4 Chinese system, but the problem still there.
• All the Oracle system message(prompt message, error message...etc) is changed to Chinese and work well already.

Hope the above information is enough to explain what I wrong in the language setting.

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Best regards,
Diviner.