When I use Internet Explorer for Windows, I see question marks or squares where characters for Chinese, Japanese, and Korean should be. How can I fix this?
In order for IE to display East Asian languages (Chinese Simplified, Chinese Traditional, Japanese, and Korean) correctly, you need to install East Asian language support. Please go to the Control Panel => Regional and Languages Options => Languages => Supplemental Language Support, and check "Install files for East Asian languages."
In order for Firefox to display multiple languages, you need to first install the Firefox language extensions. Check Tools => Extensions to find out what you have and do not have, and download/install the Language Pack that you need.