The certified refurbished computer I bought from TekRefurbs has problems.  When the PC was under heavy load,  its fan sounded very noisy and its CPU went hot( 100C) quickly . It even triggered CPU  thermal throttling.I opened the case and found some rust has already showed up on the surface of the CPU heatsink and some screws ( check the pictures). I don't think this PC meets with Amazon requirement for certified refurbished computer. (look and work like new).Asked for return in the second day. My suggestion: if you don't know inspect and test used PC, don't buy  them, even they are "Certified Refurbished".