Are you running under Windows XP or an earlier Windows version?By "totaly uninstalled" did you delete the simulator's folders (Under "\Program Files\Microsoft Games") and the simulator's files in your "\Documents and Settings\LogInName\My Documents\Flight Simulator Files" folder after the running the uninstall option that came with the simulator? That also applies to the "\Documents and Settings\LogInName\Application Data\Microsoft\FS9" folder in your boot partition.
Sometimes renaming or moving the FS9.CFG file and allowing the simulator to create a new one solves problems. That procedure will require you to reestablish any custom keyboard or controler assignments and other simulator settings.
You should also run the video and sound accelerator tests in the DirectX diagnostic program, which is available in the System Information utility in many versions of Windows, or through the DXDIAG command in the Start menu's Run popup. Compare the video card driver version in the diagnostic's report to the driver versions listed on your video card manufacturer's web site. After running the tests in the diagnostic use the option to save the diagnotic's information in case we have to consult that file later.
Robert
Near KORF