this dose not explain why your computer would not boot, however you would expect the computer to boot fine but have an incorrect time and date. time reason your computer would boot is because the RTC chip also contains 64(or more) bytes of random access memory (RAM) the clock uses to bytes of this space,leaving 54 bytes for other purposes.the BIOS. stores all sorts of information in the CMOS RAM area, like the number of floppy and hard disk drive type.etc. if the CMOS RAM loses power, the computer may not know anything about the hard disk configuration of you machine,and therefore it cannot boot.