I have absolutely no idea what I'm doing.

Hi, wondering if someone can help.
I've downloaded all the sims 3 explanation packs from g4tw on tpb, except for World Adventures, Late Night and Supernatural which I went out and bought
I installed university life following the instructions on the last The Sims 3 post to the tee. It works like a dream.
I'm now trying to do the same with the rest. The problem is that no matter which expansion I try and install it comes up with a message saying I need to insert disk 1 containing such and such.
I've followed every instruction and when none of that worked I found this forum and must have read about 60 topics in the hope of trying to find a solution to the problem. I literally must have tried everything that I possibly could try to no avail.

Please tell me there is something I've missed or a solution that doesn't involve hours and hours of downloading the expansions again
Computers are inherently evil and I haven't got a great deal of technical know how when it comes to them so if anyone can explain please use simple terms!

A very stuck girlie.

Hello,

Where did you get your base game from?

I bought that from the store as well. Sorry forgot to mention that one. An update on this though I managed to get them all to install somehow and then I did the patch upgrade and the Ultimate fix. 
Now the latest 4 games aren't showing up and when I try to load the game it comes up with "the Sims 3 has stopped working" so I gave up for a few days so I didn't throw the computer out of the window