Re: if i uninstall the sims 4 will i lose my packs?

@Stary_Night1234  When you uninstall Sims 4, all your packs are uninstalled as well—that's what the pop-up is saying.  But your account will still own those packs, just as it will still own the base game, so everything will be available to reinstall when you're ready.

You don't need to back up the game's program files, if that's what you've read.  Just back up the user folder, as in, the Sims 4 folder in Documents > Electronic Arts.  This folder shouldn't be deleted during the uninstall process, but it does happen sometimes.  Alternately, if you're very short on space, you could preserve only the saves and Tray folders inside, which hold your saves and saved households and builds, respectively.