<b>My Computer is so powerful Sauron Desires it and mortal men Covet it, <i>My Precioussssssss</i></b>
What they're talking about is a LLF will remove the Boot Sector, and Partitions, and all files from the drive, it will be pretty much factory restored, but your reinstallation of the OP/SYS will put the Boot Sector right back on the drive.
Details, Details, Its all in the Details, If you need help, Don't leave out the Details.
Wouldn't do a Low Format if I was you, I have some VERY bad memories about that stuff! Totally ruined my old Bigfoot 2 Gigs HD... or maybe I forgot something again?