First try just calling ":syntax on" inside Vim. (Or adding ":syntax on" to the end of your .vimrc file.) If that doesn't do it, then what kind of terminal emulator are your running? If you're using a terminal emulator like xterm, gnome-terminal, or konsole then in most situations it's as easy as setting the TERM environment variable to "xterm-color" and then using ":syntax on" once you're inside Vim.
If syntax highlighting works, but not for C++, I'm not sure what the problem could be. You have to name your source files with a C++ extension like .cpp or .cc but beyond that I don't know.
Last edited by taylor_venable; 07-23-2006 at 10:08 PM.
Reason: Added last stanza.