A little history of the laptop: I bought the laptop used from a friends and All the keys work except "O", "L" and the period. I bought a brand new replacement keyboard and those buttons worked fine, for awhile. I finally bought a new Wwindows Vista cd and installed it on the laptop, since it was supposed to have Vista and it had XP for whatever reason. Still nothing, when I unplug the keyboard ribbon and plug it back in, the keys work for a while and then stop. Any answers are greatly appreciated.