Most pre built machines have the BIO's locked down so OC the CPU is out. At most you might be able to OC the GPU.
ya thats all i really want to do so i cam play games better. even with the sapphire trixx program that is for the gpu the bios still wont let me oc i thing that be becouse the gpu card is intergrated mabe im not sure. is there a way to get past the bios lock