When troubleshooting a computer, why might you have to enter bios setup? list at least three reasons?

You might need to change the Boot order to be able to boot to a USB stick.
On older machines, there might be an interrupt problem with a new sound/video card that needs to be resolved. 
You might need to reset all settings to the default settings due to unexpected results.
Some BIOS allow you to overclock your CPU and the might need to be changed back due to system instability.

Hi there! the answer should be b.  online service information because the owner's manual has info on proper care of the engine and not usually on repairs and identification.-asiax      frequent answerer