My husband has a ten-year multiple entry visa. His passport expires soon. What are the steps involved in transfering his valid visa onto his new passport. Thanks in advance.

Use both the valid visa in the expired passport and the new passport for entry. The unexpired visa is still valid even in an expired passport when presented in conjunction with a new unexpired passport.

Some countries take your expired passport, I know South Africa does.

Too bad for South Africans. I guess they'll need a new visa.

Yes, that's all your answer appears to be, a guess.

The prevous answer came from the DOS website. It didn't say what to do if your expired passport was taken.

You do not have to worry. When you get a new passport from the Indian consulate they pretty much attach the old passport to the new one. The visa on the old one is still valid when used with a new passport. The new passport has information that it is the same passport as the old one.

BTW just to be on the safe side you could mention in your cover letter that there is a valid visa in your old passport and so you would want that back.

This is fine. I see this all the time and it is acceptable.