How do i get into bios so i can fix fat32.exe and my e drive?

I accidentally deleted the fat32.exe process out of my task managers process i clicked the wrong line and before i even realized what i had done several hrs had ped then i only saw that my e drive was missing from with in my computer My e drive holds all the most important things i have on the computer. old family docs, pics, videos, games and my music. then just the day before yesterday i remembered that i had deleted that fat32.exeprogramm.so i need some help here so i can restore my computer and get back the fat32 and my e drive. i cant do a system restore there are no restore points to set it too. hurry!! please be as detailed as you can because i dont kow much about fixig computers