You know that the things people can do aren't limited to just that computer, right? If you're on a home network, they can gain access to other computers on the network. They can also easily get you banned from the IRC network and can send out viruses to people from your computer. They can also very easily set your computer up (outside of mIRC) to do things it shouldn't, such as passing on viruses or doing DDOS attacks on places. You are attempting to make it possible for someone to do anything they want from your computer as if they were sitting at the computer itself. This goes beyond whether you have a backup on that computer. It is just a really bad idea.