I doubt it very much. 2,6 Ghz maybe but not 260
Windows XP, SP Service pack,
Which one? There have been three of them and you should be running Service Pack 3
Direct X is part of the video chain. You need a video card that supports direct X
However,you can also use Open GL which is another graphics standard. You can configure Google Earth to use one or the other but the graphics card still has to support it.