Toshiba Laptop wont boot, shows blinking underscore

Need help, upon turning my laptop on it immediately shows a black screen with a blinking underscore and get stuck there. I've tried removing the battery and plugin it back again (which I've read in the some forums) and it still stays the same.

I experience some other problems before this happened, which i think are related to the blinking underscore.
The system clock goes out of sync even when sync to a time server, its goes from 3:00 to 4:00 then resets to 3:00 again. The laptop in very rare occasions suddenly shuts down. I forgot to unplugged the speakers jack from the laptop(batteries and charger removed).

Laptop is Toshiba Satellite 750.

Thanks,
jay003zee

Sound like you may need to replace the CMOS battery as indicated by clock not syncing with server.

But work through the steps for Troubleshooting Windows 7 Failure to Start

gregrocker said:

Sound like you may need to replace the CMOS battery as indicated by clock not syncing with server.

But work through the steps for Troubleshooting Windows 7 Failure to Start

Hi gregrocker, is it possible that a dead cmos battery will cause a laptop not to boot?

Yes, possible, but more likely are the steps covered by Troubleshooting Windows 7 Failure to Start