Rec'd Microsoft "Streets & TRIPS" program as present.  No DVD drive on my computer.  How can it be installed?It can't without a DVD drive. But DVD drives are pretty cheap so maybe it was time to get one?
If that's not an option then check whether a CD version is available.Without a DVD Drive, you will NEED one...UNLESS you have a 2nd computer with a DVD Rom drive available and run a Virtual Drive package like this one http://www.farstone.com/software/virtualdrive-pro.htm
in which you create the virtual DVD on a system with a DVD drive and import it to the system without a DVD Drive.

((( Some DVD's dont get along with this virual drive! )))

Some anti-piracy scripts on the CD and DVD's will make the CD/DVD software on the virtual image inoperable so its a hit and miss as to if it would work or not. I use this software to avoid having to load CD's and DVD's for some games. Other games they blat that they want a physical disk!

And you only want to ever use this for software that you own, otherwise its illegal! The virtual drive software blats about this upon installation.

This software was helpful for my trip to florida when I had an old P3 Laptop that only had a CD Drive and the Map software I was using was on a DVD like yours that was a few years old. In my case it WORKED fine. I was using a Teleatlas product like shown here http://www.teleatlas.com/OurProducts/MapData/NavigationCDsDVDs/index.htm