An electronic device includes a BMC, a BIOS, and a UART connected to at least one external input device. The UART includes a number of registers. The BMC is connected to the UART to initialize the registers and is also connected to a south bridge and transmits a restarting signal to the south bridge when the BMC is restarted. The BIOS is connected to the UART and stores input from the input device to the registers, the BIOS is also connected to the south bridge and detects whether the BMC generates the restarting signal to the south bridge. The BIOS then enables or disables the registers to store or not to store the input from the external input device according to whether the BMC generates the restarting signal.