Hello, I've compiled R-2.15.2 for windows x64 and try to do a simple test : ------------------------------------------------------------------------------------------------------------------------------- A <- matrix(rnorm(3e8), 3e4, 3e4) B <- solve(A) Erreur dans solve.default(A) : impossible d'allouer un bloc de m?moire de taille 6.7 Go ------------------------------------------------------------------------------------------------------------------------------- to solve this problem in R-2.13.2 (windows version) the following modifications were needed : in "R_HOME/src/main/memory.c" to modify the definition of the function "char *R_alloc(...)" ------------------------------------------------------------------------------------------------------------------------------- #ifdef WIN64 #define SIZEOF_SIZE_T 8 #endif ------------------------------------------------------------------------------------------------------------------------------- what I have to change in R-2.15.2 to avoid this problem of memory allocation ? Thanks!