client, Warren, reports CMOS mismatch errors at startup. Further conversation with Warren reveals that he had forgotten the startup password he assigned in CMOS, and he had to clear all CMOS settings for his computer to complete a successful startup. Although he can now start his computer, he continues to observe CMOS errors each time he starts the computer. He replaced the CMOS battery, but the problem continues. Which component should you investigate first to resolve the problem