You probably don't have the Arial Unicode MS font installed. No problem, you can just use any of the Korean fonts instead.
When you execute your insert statement you will have to have a korean character your statement. It will have to look something like (I hope the korean characters come through)
INSERT INTO tmp VALUES N'???'
You might have to open up Charmap and find some Korean character and copy and paste them into your Query Analyzer SQL statement.
Your Insert statement is putting in the word 'testing' and it is correctly storing that value. The SQL statement will not do translation.
SJ