I've bought the LFS S2 license in the last year [2016], and in the last Monday, i've installed my windows again, and i lost my last unlock, can you guys help me ?

I think you guys could to remove the number of unlocks per player, or minimize the unlock give time.

Actualy, when you buy an account, you get 3 unlocks, which is sufficient. Also, you probably unlocked more than once in a single week, as far you receive +1 unlock every week (but it's not unlimited).

Removing unlock limit means allow a shared account. My syggestion to you is to wait til next week

If you've unlocked LFS 3 times and have no more unlocks for this week, you'll need to contact the devs at https://www.lfs.net/mailus

LFS will automatically give you an extra spare unlock once a week (every friday morning), up to a maximum of having 2 spare unlocks available. The number of unlocks you have left can be found on your status page.