Don't try and get a PS3 controller of any sort working on your PC. Just don't. If you're asking a question like this, you're not prepared to go about trying to get them to work. There is no "plug-and-play" driver/software for PS3 controllers to work with a desktop computer.
And no, there isn't anything to "convert" or more correctly, "adapt" them, it doesn't really work like that. If you want those fun toys on your PC to just work, get xbox accessories. Many people have been trying to get this stuff to work for a long time, people greater at coding and circuitry than you and I combined. If they haven't gotten it yet, we don't stand a chance. Sorry to burst the bubble, I hope someone else can chime in to prove me wrong but, I can assure you it probably won't happen.