I want to update my game with new DLC, can't remember where I downloaded my version from!

I run it from an ISO, there is no installation, just a folder in my documents. I *most likely* got it from here or somewhere this website recommended (sims architect maybe?) I'm not sure. I've only just started playing again after a break, my most recent DLC is Jungle Adventure. So I'm not really sure which route to take to update my game (and keep my saves intact).

Another thing, if I download a complete version and start from scratch, will I be able to keep my saves if I just copy of the folder from my documents?

Many thanks!

I'll start with last question: yes, if you download complete version your saves will work fine. Just make sure you remove/update your mods first.

But there's no need for that! It sounds like you have a version that Tarac uploaded here. If you want to update it:
1. Mount the .iso file.
2. Copy files from .iso somewhere else (for example "C:\Program Files\The Sims 4").
3. Update the game with G4TW releases or my repack.

If you want to use G4TW releases, use this guide: https://www.games4theworld.club/t21806-must-read-how-to-install-the-sims-4-correctly That will be 42.9GB to download.
Or use my repack (link in signature), that will be 8.91GB.

Thanks so much, I used your repack and it worked beautifully!

I never knew you could just copy files from an ISO to create an installation folder like that, so I learned something new today too!