BSOD problems can be hardware and or software related.
How old is it? if it's more than three years old, replace the internal cmos battery regardless.
Make sure to first power down the device, then disconnect the main power cord, and for a laptop, remove the battery to the device before touching, or removing anything.
Also, make sure to ground yourself to the computer cases metal, while working on it. Either by holding on to the case, or use a grounding strap. This is to avoid any errant static discharges.
Laptops can be tricky to get to the battery, but desktops are easy. In most cases it's a 3.3 volt coin battery, and it should state the correct voltage on the battery itself. Best bet is to check the manufactures docs, regarding battery type and replacement on a laptop. You may have to disassemble a good portion of the laptop, to get to the battery.
After replacing the battery, you will want to review your bios settings, to make sure they are all correct, so it identifies your drives, and defines the boot drive.
