Hello everybody; I have an executable file called WGRIB.exe This is a small potatoes type file that converts atmospheric data from a gridded binary format to ASCII text. I have used it plenty in the past but only on Win98 and NT (build 4 I think). Last night I tried to use it in the Dos window of XP, but it won't werk. I keep getting a stack fault error. I am assuming that this is an XP issue. Does anyone know if there is an XP update or driver that allows one to execute older DOS programs on XP ?? Has anyone experienced similar problems of this nature? ANY ASSISTANCE would be GREATLY APPRECIATED ! Muchos Gracias , Merci Beaucup, Tanka, Grazie, Domo Oragato !!!!