I have to say that i actually love this little computer and its GREAT DEAL!!! so I purchased the (HP EliteDesk 800 G1 SFF High Performance Business Desktop Computer, Intel Quad Core i5-4590 upto 3.7GHz, 16GB RAM, 1TB HDD, 256GB SSD (boot), DVD, WiFi, Windows 10 Professional computer) shipped very fast [ 2-day shipping, ordered it sunday night and arrived Tue later morning] it was packaged wonderfully and booted up Fast about 15 sec ,  the set up process was very simple and easy. Once i got access to my desktop , I opened my *File explorer; to check everything was as advertised on amazon: the CD-ROM disk was actually DVDRW instead of just DVD drive , Very nice! it came with QQfamily mouse and Keyboard but i used my own. Next , i looked for the HDD and SSD and only found that it showed the 256 SSD and no trace of the 1TB HDD but i kind of had a heads up as the first review was written by someone who said they had issue locating their HDD in file explore and disk management but that they just opened it up and seen a wire loose and that fixed the issue. unfortunately that did not help me , I opened my tower up checked the connecting wires but it still wasn't seen in file explore  :( so I went into disk management  and there it was :) it was online it was partitioned but it was not assigned a letter , so i did what YT video said to do an assign it a letter and even formatted it  and i thought i had figured it out , til i restarted my computer after a windows update and then tried to install a game and wanted to install it on the HD instead of the SSD where my OS was and i couldn't find it , so back to disk management i go, only to see that the letter i assigned the HD was no longer there SMH , so change drive and letter path 2 more times and to check if it held; i would restart but every time the same thing would happen..  so i just clicked on the HD - deleted the volume and went through the whole process with wizard thinking that would help. NOPE! So , i was frustrated at this point , so i went on YouTube and found a way to *Format a drive using Command prompt/diskpart and followed it step by step and it was so easy- the Video is by Chris Piedra* OMG! when i tell you it worked , i found it in file explore and when i finsihed i got the notification in my task bar asking what setting i wanted for that drive ( which i had not gotten once before) not only that but when i restarted my computer it was still there!!! so if you choose  to buy this lovely computer and can’t find the HD or see the HD just format it using Command prompts and diskpart and i am no computer expert at all