NEC 1300A DVD question

I bought one and it seems to fail to play DVDs.  I wonder what I need 
here.
I got three DVD softwares (with 5 minute limits before registration) and 
they consistently give me:  no device found;  device not ready;  no dvd 
disc in device;    . ONE played one time, picture and sound seemed OK. I 
thought " I got it going"  stopped the software and tried a second DVD 
disc.  It never restarted.

Which software will play factory DVDs, homemade (VCD MPEG1) DVD-Rs and 
MicroSoft video files ? 
I don't need encoding, ripping, or other stuff from the DVD playback 
software. I have it already. 

-- 
Robert Hedges
http://www.ecsd.com/~rhhedgz1/