I would enter the bios and go to standard cmos setup first. You will find the B drive listed under the floppy A.( both are reserved for floppy drives) set it to not installed.
then go to (probably) intergrated peripherals. Look for a setting like " reset configuration data" set this to enable.
F10 to save and reboot.
This should re-write your cmos checksum.
see if this improves things.;-)