This is a custom built  Windows computer. It works when it has a hard drive with an appropriate OS such as Windows 7 is installed. IT DOES NOT COME WITH A HARD DRIVE OR AN OPERATING SYSTEM. This is a 32 bit system. It is vintage and will be mostly incompatible with newer softwares. 

This is what is included:

Antec Sonata-III case

Q6600 (running @ 3GHz/1333MHz FSB) INSTALLED

Freezer 7 Pro INSTALLED

Abit IP35 Pro motherboard INSTALLED 

4GB Corsair DDR2/800 INSTALLED 

Video Card with VGA, DVI, and HDMI ports - not sure what brand or model, see photos INSTALLED

20x Lite-on DVD/RW INSTALLED 

It includes 4 removable trays for its hard drive slits, and several cables for connecting SATA drives to the motherboard ports, plus a 2 extra drive trays that maybe for a different model Antec case that may also work in this one.  

This computer ran Windows 7 Home 32 bit for years. It was in use as a local server and was still running Windows 7 Home without issue when it was shut down earlier this year. 

It is sold as-is. 

Any questions, please ask.