oki then
thanks for advice

i think it's right thing to do
practically :

1- save the resident flash (internal memory 2GO)
2- let igo8 as it is
3- remove old maps on resident flash folders (\....\CONTENT\MAP )

that sound good

(ps: for info : i'm sure that an internal 2GB mem: because it embedded the europe map of 2013 without any SD card (when i used it)
many thanks again for help