Hi!! How is it possible to use the MASM macros that are there, like lcase.asm ?? Acid_Cool_178
lcase.asm is not a macro, it is a source code file for the masm32 library. A library is a set of one or more pre-compiled code procedure you can have added to your program. Here's how it works. First, you need to tell your source code .asm file what the procedures in the lib look like (ie, the PROTO definitions). You do this by adding the line "include /masm32/include/masm32.inc" to your source. masm32.inc contains a prototype for every procedure in the library. After you have done that, you can use the lcase procedure just as if it was any procedure you had writen. So masm can find this code, you also need to tell it where this library is by adding the line "includelib /masm32/lib/masm32.lib" Actually, it's not masm but the linker that needs this information. After masm builds your source to an object, the linker takes this object and starts looking for whatever is still open, here it would be looking for the code to lcase. Since this code is in the masm32 lib, the linker can find it and add it to your program object. Once all references like this are found (resolved), the linker adds a header and converts the object into an exacutable (ie, a program).