Ended up wasting my time trying to make it work, and now need to pay for self-shipping it back, and pray someone will at least refund that.As a computer technician with more than a decade of experience,I was horrified to find out the condition this pc arrived.Some parts were broken, other missing,It stopped showing display after 3~4 hours of use.Needless to say, I've tried all the regular solutions,this by far is my worst purchase on amazon.in addition:1. power supply screws completely missing, all three of them. Plugged the power cord and the power supply jumped inside the case!!! who in his right mind can call it "certified refurbished"?2. The product page clearly stated "no signs of cosmetic damage visible from 12 in away".no, it's not only there are signs of cosmetic damage there is also physical visible damage. (the package was good so it definitely didn't get damaged on the way)3. when I just received it, I heard something dangling inside I thought it was a loose screw but found out it was a plastic piece of the PCI Express connector, which is broken, and I cannot use it to add a graphics card.4. The RAM sticks mismatch, they are completely different brands! this is not acceptable by any means, not even mention you cannot add 8Gb stick to upgrade to 16Gb RAM correctly. (well you can use 2 sticks of 4Gb but that just awful)