No that's fine - you didn't mention it was from a DVD camera though,
but I don't expect that to make any difference. I saw a review which
mentioned this process here  (scroll down the page)

http://www.ciao.co.uk/Sony_DCR_DVD92__Review_5541198

As that review mentions, they're saved as standard DVD disks so they
can be played in a standalone DVD player. The thing is, the .IFO file
are really like an "index" of a book, and actually contain only a few
hundred characters of information.

On the disk as well, you should be able to see a folder called
VIDEO_TS which contains a number of .VOB files, each up to 1 gigabyte
in size. They're the ones which actually hold the video data, not the
.IFO files.

If you're takling about playing the DVD, the best bet is in a
standalone DVD player. If you can't play them on windows it's because
there's no MPEG video decoder installed on your PC.

Unfortunately the decoder has to be paid for due to licensing issues,
so you'd have to either have a DVD player program already instaled, or
install a decoder for windows media player to view them.

A good DVD decoder (with a 30 day free trial) is at NVidia's website :
http://www.nvidia.com/object/dvd_decoder.html

The review above mentions TMPegEnc which is worthwhile getting if you
need to edit the video, although as it's already been compressed, it
won't be as good when saved as a standard DV (tape) camera.
http://www.tmpgenc.net/e_main.html

HTH
Cheers - Neil