I just borrowed this game from a friend, and this little slug thing, ATTACKED ME!!!!! and the loading screen thing said that guards would help, BUT THEY DIDN'T! needless to say i almost died.

describe "slug thing" please and where you were fighting it.

at the beginning of the game, it had like a shell or something

Was it something i said? to change their disposition to not help me?

You almost got killed by a scrib?! What class and character are you playing?

You usually have to run by the guards, they won't help unless they see your attacker.

i wasnt exactly "fighting" i was trying to get the guards to do it for me bu they wouldnt.
edit: i am playing a nord. i was just dikeing around to see the combat capabilities of the common guard

ahh. Guards are lvl 20 with improved endurance and strength.

lol you gotta watch out for those scribs. It seems to me that the guards are pretty random in when they attack creatures. I've seen imperials in seyda neen chase down mudcrabs and guards in balmora attack cliff racers, but when I lead a creature into town that I need help with they seem to ignore it. Maybe they just don't like the player.

Guards normally will help you fight creatures, (but they do not help you fight NPCs)
This guard just might not have seen the battle. Meaning that his AI didn't register it. If you hadn't attacked the scrib yet, he also might not have considered it a fight.
Also, a guards Disposition has no bearing on how he fights.