updating latest sims 3 patch

I just bought The Sims 3 Island Paradise on a online download. It downaloaded and that was all working fine it then got to the installing part and came up saying "please update the latest version of the sims 3 before installing". I then went onto the launcher and patched my game thinking it was patched and attempted to install Island Paradise again and it said the exact thing, not knowing my stuff i just believed that there was another patch not realising that it was the same one and only realising after i had done it 4 or 5 times. I know i need to update because at the bottom where it shows all the games in little circles, my latest one is seasons so my game does need updating howver i cant get past this certain patch and i really dont know why? I just bought this new EP and i am SO excited to play it, i just need to update the game!

If anyone can help i will be SO greatful

Thankss,

Aimee

PS i am not very teach savy so i will need quite simple instructions