Thanks, Pescado. Appreciate the information.

I installed the UC, started up the game, and had no problems. But according to MTS at this thread, http://simswiki.info/wiki.php?title=Game_Help:Ultimate_Collection_FAQs#Question:_Will_my_old_neighbourhoods_work_with_UC.3F, since I had the store installed, I had to follow instructions on another site to use my saved neighborhoods. The site is this one http://www.simsnetwork.com/simpedia/the-sims-2/editions/the-sims-2/specials/restore-sims-2-store-edition-in-ultimate-collection. I followed the instructions. Since most of my games were downloads from Origin and their store download would not work (saying I didn't have Sims 2 installed), I used a University Life collection CD. When I tried to load the game, it asked for the CD then said I was running the wrong version. I did something really stupid. While I backed up the games, I spaced off backing up the registry. Is there a way to fix it so I can use the store version, or is there a way to get the correct registry which I had changed per the instructions? If not, will it correct itself if I uninstall and reinstall the game from Origin? Thanks for any help.