Do you have another burning program such as Roxio or Nero that often
comes as an older or limited version on a new computer? If so, see if
it will burn a CD properly. This would help establish if the problem is
in WMP or in something else. Also will the WMP play back a commercial
CD properly? Sometimes the CD drive, even on a stand alone DVD
recorder, gets out of adjustment or starts to develop a problem. At
first CDs it made may only play back on the drive that recorded them
and perhaps a few other players. In time it may not play back any CDs.
I don't know what version of WMP you have. Does it have a setting that
removes space between tracks and joins all of the tracks into one large
track? One of my burner programs allows this, and if this setting is
turned on you get just one long track on the CD. Unfortunately there
are many possible problems that could cause your problem, and running
down what it is can be difficult. If you happen to have a Nero suite of
programs, it may have a diagnostics test for your drive that sometimes
can find such problems.