I have Windows Vista installed, all of a sudden when I open autocad and the startup small widow appears and I try to open a existing drawing or new drawing, a window informing fatal error unhandled with a bunch of letters and number comes up and when I click OK the whole program quits,

I have uninstalled the program and reinstalled and it works OK, but a few days later I go to use the program and its got this error again,

has it got something to do with Vista do you think?, and could any member please help?,

..........Edmund.........