Re: graphic card?
Ati 9550 is not all that bad. I believe it's an agp card, so it allows for 8 lanes of data. Your standard intergrated onboard video should do a swell job of just playing dvds, and video files. You know you need upgrading when video is choppy or the dvds cut off in the middle, otherwise you should be fine. Video cards are more needed for games and graphics intensive programs.
Rig -- Emachines T5026, 3.06ghz P4, 300W Bestec PSU, 160 sata hd, 512mb dual channel 3200 ram @ 3-3-5-8, ATI Radeon 9250 pci, dual layer 16x dvd+/-rw.