I've purchased several of these refurbished PCs over the years and I'd have to say this was the cleanest one I've ever seen.  It was technically built in 2014, yet the fans and motherboard had zero dust on them.  The 16 GB of RAM was spread across all 4 slots, so if I wanted to upgrade, the best I could do would be to replace a pair of the 4GB with a pari of 8 GB.  The PC did not come with a Windows 10 key attached.  So I did need to email support.  Omar was extremely helpful and was able to get me the Windows 10 key in less than an hour so I could load the OS onto a separate SSD I had purchased.  All in all a great small form factor PC for the money.