I had already returned this once before, to this vendor.When I got the replacement, it booted up fine, and has a good processor, which is why I bought it.Occasionally I I use this work station to play a DVD movie, but I didn't think to test this one.Works on a few of my DVDs, not all. I tried cleaning the optical part of the reader with alcohol. Didn't matter. Still only works with some DVDs,  not all.I am probably outside the window of returns, and I just can't keep returning this stuff.I have extra DVD players here, and could hook one up.But that is not the point. This desktop computer is still defective.Anybody who thinks 'refurbished" is as good as new is in a different reality.