No, Vietnamese is not a Chinese language. While Vietnamese has been influenced by Chinese culture and language, it belongs to the Austroasiatic language family and uses the Latin alphabet for writing.

It seems that Photoshop 7 cannot handle the Vietnamese language, because it cannot work with Unicode.

There are approximately 76 million native Vietnamese speakers worldwide. Additionally, there are millions of other people who speak Vietnamese as a second language.

Alexander de Rhodes used Roman Alphabet to create a language first called "National language". Before it was created, Vietnamese used Mandarin, Cantonese,... During the communist government's time, chairman of the country Ho Chi Minh encouraged National language to be spoken as Vietnam's official language, and it remains the official language until now. It was called Vietnamese by foreigners.

Not a Vietnamese language.