{ PJ> in PROG1.EXE i execute PROG2.EXE, ok... PJ> PJ> in PROG2.EXE i want to check if PROG1.EXE is running, PJ> PROG2.EXE can not start without PROG1.EXE starting it... PJ> PJ> sounds crazy? :) PJ> PJ> i need a routine for that (please help me!) If you understand assembly and interrupts here is what I'm doing: I'm hooking int 96h and using it as an installation check. When it is called with AX = to a magic number (MagicNumber below) it will return another magic number that says that it is installed (ReturnValue) below. Try this: PROG1 : } Uses Dos; Const MagicValue=$1248; ReturnValue=$8421; Label SaveInt96; Var InstallSaveExitProc:Pointer; Procedure InstallCheckIsr; Assembler; Asm cmp ax,MagicValue {Is it an installation check?} je @@InsCheck {If so skip next part} db EAh {FAR JMP opcode} SaveInt96: db 0 db 0 db 0 db 0 {After program is running, this will jump to the old interrupt handler} @@InsCheck: mov ax,ReturnValue {Return the ReturnValue in AX} iret {Return from interrupt call} End; Procedure UnInstallCheck; Begin SetIntVector($96,POINTER(SaveInt96)); ExitProc:=InstallSaveExitProc; End; Procedure InstallCheck; Begin GetIntVector($96,POINTER(SaveInt96)); SetIntVector($96,@InstallCheckIsr); InstallSaveExitProc:=ExitProc; ExitProc:=@UnInstallCheck; End; PROG 2: Uses Dos; Const MagicValue=$1248; ReturnValue=$8421; Function Installed:Boolean; Assembler; Asm mov ax,MagicValue {Check to see if PROG1 installed} int 96h xor bl,bl {BL temporarily holds the return value, the "xor bl,bl" sets it to 0 (False)} cmp ax,ReturnValue {Is PROG1 installed?} jne @@Exit {if not skip next instruction} inc bl {set BL to true (0=False and 1=True for Boolean)} @@Exit: mov al,bl {return Boolean in AL} End; Now, in program 1, call InstallCheck when you start the program, it will clean itself up when the program ends. When program 2 loads, just have it call Installed, if it returns true then Program 1 is loaded. Finally, make sure that the constants MagicValue and ReturnValue are the same in both programs, otherwise Program 2 will never think that Program 1 is installed. (You might consider putting them in a unit to avoid confusion. One final note: These routines are untested, although they should work, I'm not perfect. If you can't get these to work, let me know, or if you want to know more about how they work, let me know. Hope these help.