Windows 10 Professional 64 bit, Activation code is on the tower; the best operating system for business.
Processor: Intel Core Quad-Core i5-2400 3.1GHz (Turbo up to 3.4GHz) 6MB Cache;
USB Wireless Adapter to connect the Internet.
DVD ROM,
USB Keyboard,
Mouse,
Integrated Audio,
10/100/1000Mbps LAN;
Slots: 10 x USB 2.0 ports,
2 x audio-out jacks,
1 x microphone jack,
1 x RJ-45 Ethernet port,
1 x VGA port, 1 x line-in jack,
1 x serial communication port.
16GB DDR3 (PC3-12800) Memory (4 slots, supports up to 16GB),
2TB 7200 rpm Hard Drive,
Intel HD Graphics.