Hey neomorpheus,
First, U'll need to get the make, model#, etc of the laptop that U reformatted.
2nd, Take that info & search the manufacture's website.
3rd, when you're search is successful (ie: U found a User's guide/manual for YOUR specific laptop)
4th, view the info that U've obtained & C if there's any key combinations that must be pressed during the POST process. If & when U've found the key combination that'll let U enter setup then HALF the battle's done.
5th, some COMMON key(s) combination(s) that'll let U enter CMOS SETUP / BIOS are the: "DEL" key, "F1" key, Ctrl & ESC;
However, some manufacturers have their own SPECIFIC keys 2 do this. It all depends...Chao!!!
"So I took the roll and ate it; In my mouth it was sweet as honey but in my belly it was bitter as wormwood"