Do you need all patches when reinstalling?

[SimSPY]

I just got a new computer with Vista.  Here is my question, because I just cannot remember.  I have to reinstall Sims2 from the beginning thru Nightlife, and then I am adding OFB and Pets for the first time.  Do I need to install all patches since the beginning, or will all expansion packs contain the previous patches?   I think that the latter is the case, but I may need the Pets patch when done.   Could someone please remind me how to do this?  Thanks very much.

[Sleepycat]

the EPs only check to see if the base game is patched so you should patch every EP yourself.

EPs don't patch the other EPs.