So you're using mIRC incorrectly. windows are not meant to be your data buffers.. they come with the obvious inherent drawback discussed in this topic. You either acknowledge it and change your methods to the proper ones, or you stay stubborn and deal with the limitation. This isn't just a problem with mIRC, it's a problem anytime you abuse the creation of HWNDs to store data, so there's little mIRC can actually do any different than..like, any windows application. Start using hash tables or start using dlls if you need the speed... OR use /filter on files, since theyre a) cached anyway and b) not all that much slower than windows.