Many of you should know about it, its the thing that lets you choose which operating system to run, and then starts it for you. Its also what can almost stop a computers usability with a few clicks of a button. You have probably also had problems with it in the past, maybe a dead os listing, maybe not all the oses are there, or something more serious.
I know people who think the solution to whatever bug or problem in grub is to reinstall the machine. If you are thinking of doing this, don’t. The easiest thing to do is get a live cd and fix the grub issues there. Here is even a good tutorial on how to do so:
If grub was overridden by a new install of windows or if grub has an incorrect/missing boot item:
You can fix the random errors that you have no idea how they got there by reinstalling grub, and if that fails, you need a new pc, because reinstalling grub is the same as reinstalling everything on your pc to fix grub.
So please, for the love of grub users everywhere, don’t format everything to fix grub, use a liveCD to fix it instead.