Installing Sims 2 expansion pack

For The Sims 2, go to My Documents\EA - and copy the "The Sims 2" folder and paste it somewhere else on your computer. You can rename it to "TS2 Backup Original"... then add one expansion and then do the above again (copy/paste the "The Sims 2" folder) and rename it to something like "TS2 Backup University" (or the name of whatever expansion you're adding).

But realize that these backups will have your people and neighborhoods EXACTLY as they were at the time you copied them. So if you install an addon (or 6) and then play for 3 months, and then decide you want to go back to a previous backup, you WILL NOT have all of that work that you've done.

If you have the hard drive, space, though... I would recommend making a backup after each expansion addition... and then make a backup once a week or two to save/backup your progress. Also, if you download a ton of custom content, like me, keep a copy/backup of that folder with your other backups. =)

Good luck and have fun!

Copy the neighborhood files and put them into documents then when you uninstall and reinstall move the files back in merge them and you will have all your towns.
Happy Simming