quick delivery , Received GX620 3.2 Ghz instead of GX520 3.0Ghz , Everything else as advertised .Comes with xp-prosp3 pre-installed. Had it up and downloading windows updates in 20 minutes from opening the box.Keyboard and optical mouse are o.k. cheapies.Socket LGA775, DDR2 , 1xPCI-X-16 slot , 4 mem slots , dvd-rom/cd-rw , 3 free sata ports ,8 USB 2.0 , 3.2 P4 prescott processor (.90nm.) Runs Silent . .Overall very satisfied!!!!!!!!!!!