I want to make a new operating system for PC. I know C, but have no idea about in which compiler can I do it.
Don't worry so much about the compiler at this point (gcc would be fine though). You need to think about all the other problems involving getting an OS to run. I strongly suggest you dive in to some of the communities around "hobby OSes". This will give you an idea of what's really involved in OS development. Also take a look at some alternative OSes that are already out there, like Minix and perhaps Haiku. OS development isn't something you can do alone and expect to make progress overnight, but it's a worthy endeavor in any case. Good luck!