Didn't work either :S I don't know what else to do. If I open the controller app first, my BHO cant communicate. Worst of all, when I use setsecurityinfo, I get no errors. And my app works, because if I turn off protected mode or open IE before my controller app it works fine. A lot of BHO developers are asking their clients to turn off protected mode in order to use their soft, I think I'll need to do the same :( -- modified at 9:42 Monday 30th April, 2007 I FIXED IT!! Thanks mate, using SE_KERNEL_OBJECT and don't allowing the BHO dll to init if is in the controller app address space it started to work :D