If there are any Chinese folder name exist in your Outlook folder list and you want to change it back to English folder name like this one,

Procedures:

1. Click "Start" menu -> "Programs" -> "Microsoft office" -> "Microsoft office tools" -> "Microsoft office language settings". Then change all the language settings to English
2. Go to "Control panel" -> "Regional and Language Options "
3. From the "Regional Options" page, change the "Standards and Formats" setting from Chinese (Hong Kong S.A.R.) to English.
4. Click "Start" -> "Run..." and type in the command: outlook /resetfoldernames then the folder name will be reset to English.
5. You can then change the language settings back to Chinese for item 1 and 2 if needed.