TssP wrote: IA64 (orAMD64) processor with windows xp 64bit beta WinXP 64-bit beta does not run on the IA64 architecture, only on the AMD64. If you cast a pointer to an integer at any stage, use the ULONG_PTR data type, which is guaranteed to be the same size as a pointer, no matter what platform you're compiling for. Also use SetWindowLongPtr() and GetWindowLongPtr() instead of SetWindowLong() and GetWindowLong() for the same reason. There are other things to watch out for, but you'd best go through each method call and make sure it's going to work. See here[^] for a few more things to watch out for. Basically, check that any variable size changes are not going to cause you any problems. Ryan "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"