I am building my own PC and I have brought all the parts that I will need. I am using an ASRock Extreme4 Gen3 motherboard on which I will attach all the parts. I assembled the whole system first time and tried switching on the computer. Everything worked fine except for one thing; mouse and the keyboard arenít being accepted by the motherboard. I have assembled many computers before this and I have worked on many motherboards including MSI, Gigabyte, Asus and many more. But this problem has occurred first time in my whole working experience. I know many times the motherboard doesnít accept graphic card or hard disk, but I had never seen a motherboard rejecting a mouse and a keyboard. They work fine in the BIOS menu but as soon as I exit it, they again get rejected by the motherboard. I am using generic mouse and keyboard. So I disable the USB port, this enables the keyboard in the system but still I couldnít mouse to work outside BIOS. I thought that ASRock motherboard must be incompatible with a specific brand of mouse and keyboard, but it seems like none of the mouse and keyboard is being accepted. I have tried five different brands of mouse and keyboard and none of them worked.