I need a little help...

[jrbami66]

I've started up the program, and it came up with an error message, saying I don't have any open cl installed and if i want to just use c p u mining, then this doesn't matter. I clicked OK, and then entered my pool information for the slush's pool, and went to the devices section, there was only 1 device, "no open cl devices," I then clicked start mining, and got the error, nothing to mine on, exiting. I'm now stuck and not sure what to do to be honest, so if you could advise, i would be very grateful.
What do I need to do to actually start mining? Thanks...