I made a program in Turbo Pascal 7.0 that sometimes reads sectors (using REGS and INTR standard procedures) from a floppy disk and writes it back to the same sector when my program do some modifications to the information, But sometimes in Windows 95 (DOS box) when I do this operation many times, the program "read" the sector but not writes its contents back (no writes anything). When I try this program in Windows NT (MS-DOS Console), it reads the sector but not writes back anything(!). What happen in this two cases? I need DPMI or something? The program works without problems in Win95 DOS Only-Mode and DOS 6.x. Thanks a Lot!!!