It will only compress using the Instant mode, the other 2 produce a zero bytes exe and/or crash when there ment to start the compress bit, I have tried it from inside VS and from a command prompt but get the same result and no error message which makes it hard to tell why its failing. I can run exe's compressed by it in any mode as I have tried ones compressed on xp, I just cant get it to compress for some reason, there was someone else that mentioned it on pouet.net, they get the same results as me but I havent seen anything on fixing it posted at all.