They werent anything, they were unreadable files, that you just drag into the downloads folder

I accidently switched all the .package files to the sims 2 custom content installer, and now all of those files are switched to that, will it interfer gameplay? do i have to switch it back, and if so,how??
I haven't played on a pc in a while i've been mostly on my mac, and i totally screwed it up Help Pleaseee