Operating System : Windows 10 Home & Pro MAR, Ubuntu Linux, Free DOS Chipset :i945G Express Processors :Intel® Core™ 2 Duo, Intel® Pentium® D9xx/D8xx, Intel® Celeron D, Intel® P4 Memory Support :Four (4) DIMM slots , Up to 4 GB DDR2 667MHz SDRAM  Hard Drive :Serial ATA II 80 / 160 / 250 GB Removable Media :16/48-speed DVD ROM, DVD SuperMulti writer, 48/24/48/16-speed CD-RW / DVD ROM Expansion Bays :External: Two (2) 5.25-inch, One (1) 3.5-inch, Internal: One (1) 3.5-inch Expansion Slots :One (1) PCI-e x16, One (1) PCI-e x1, Two (2) PCI Graphics :Intel® GMA950 Audio :Realtek ALC260 Communications :Realtek RTL8110 I/O Ports :Front: Two (2) USB, Audio I/O  Rear: Four (4) USB, Audio I/O, VGA, PS2, Serial Input Devices :N/A N/A Power :300 Watts Passive Dimensions :372 x 202 x 376 mm Weight :11 kg