Could you be a little more precise ?
You upgraded XWA to 2.02 version. Does the XWA launcher starts ? Thats the very first window that loads, where you can choose to play, check your hardware and pilots etc.
Where does this merror message shows up. If it's in the game (inside the liberty for example) when you choose a mission, then you probably have the wrong disk in your cd-rom...
"The ability to speak does not make you intelligent"