(After upgrading from 7004 or 7008 or 7392 to 7720 (Windows Phone 7.5), many friends' Windows Phones were very sad to find that Chinese did not appear on their phones as expected. That is due to the limitation of the size of its own ROM. Although Windows Phone 7.5 supports Chinese, the default upgrade is only in English. To obtain the Chinese language, HTC's official customer service needs to support it, which is also a trouble.)