i jus d/l ed nasa worldwind. it took 8 hrs to download on my slow 64kbps connection when installed it said i need to d/l .NET and it installed. ok, i d/l ed .NET but when i click on dotnetfx it gives error. it says dotnetfx.exe is not a valid win32 application??? what to do? dotnetfx is currently d/l ed to my desktop. should i place it into windows directory or something??? edit: i searched google about this but didnt get solution. i 've downloaded this file 2 times and it gives me the same error again.