The X200 is between 0% and 100% better, depending on the game. The X200 really shines with it's DirectX 9 support, which GMA 950 does not support.
I'm pretty sure the 1012 won't run a P4, and I don't think the 1013 will run a Mobile Athlon 64. With the 1012 your stuck with Celeron M or Pentium M, and with the 1013 you're stuck with Semprom M or Turion.
In one of the copies of Windows there's a boot.ini file in the root of the drive. In Windows explorer, Tools>Folder Options>View and uncheck "hide protected operating system files." Now somewhere, probably in the root...