when i was saving my word document, it sudenly changed to some languge i cannot understand i guess it is chinese language. I suspect it could be virus attack. please help on how to recover my document back to english.

You could start by highlighting just one sentence and then changing the font to an English language frnt such as Arial. If that works, then do the same for the rest of the document.

Can you just give us one line of the document, so we can see what kind of language it is?

this an extract of the document:
ᘆ虨琑 ᘆ졝 ᘆ䡨杓 ᘆ表� ᘆ繨᝗ ᘆ쑨⤂ ᘆꡨ ᘆ驨ܛ ᘆ難པ ᘆ坨籽 ᘆ潨偂 ᘆ艨佄 ᘆ왨꼮 ᘆ杨ᐁ ᘆ鬜 ᘆ剨� ᘆॖ ᘆὨ⍊ ᘆ靨詎 ᘆ≨蹨 ᘆ⁨Ꝣ ᘆ睨푤 ᘆ蝨꠪ ᘆ遨猘 ᘆ텨 ᘆ䑨豾 ᘆ콨꼭 ᘆ╨謪 ᘆ湨伾

Ok, it might be something todo with a macro virus: http://support.microsoft.com/kb/187243 eitherwise it might be worth asking microsoft, you could either email them or tweet them as they have a support account on twitter.