A file extension of .aci is not a regular DVD - it's just a computer video file copied to a DVD.
If you want to play it in your regular DVD player you'll have to convert it to a format your DVD player can handle.
Safest format is either a true DVD of a VCD (on the assumption that most DVD players do play VCDs (Video CDs). SVCD is also a possibility - better quality.
There are loads of video file converters - just hunt around with Google for one.