You can unlock LFS on more than 1 computer but that is for a single account, if your brother wants a seperate account and wants to race online then you or he will need to buy S1 or S2.
It is fine to share a single account on two HOME computers. (being in the same household) and play over the LAN. I never did this since my dad wasn't interested, but I talked to the developers about it back when I first got S2.
If you want installations on two computers, you'll need to buy two licences.
If you want to race each with your own seperate name and stats but on the same computer you'll need two licences running on seperate installations.
If however, you don't mind sharing the same name and stats (and infractions, bans and reputations, should the other misbehave, something that you'll have little or no control over, rememeber) then just use the one licence.
Why am I sad, I mean I have other accounts, not like I can't afford to buy licenses, what I do with my account is my problem, if I get banned, then so be it.
Soo how many do you have then? Seems a waste to me, i don't see the need for them, people that buy second accounts are usually the guys that have ****ed people off and have bad reputation, i thought yours was pretty good so just seems weird.
I have other accounts because I have bad rep on here, also just to do other things, like I actually have a drift account
and my other is for racing.
Edit: 3 Including this one, and before you ask like others, I won't give names.
Edit2: Although 'rep' actually doesn't bother me as much as it usto, now I don't care about what most people think, I just play the game, have my fun, and if anyone doesn't like it, i'll throw abuse back at em, and I can annoy them more than they can annoy me, and I will.