I know the general rule is to never delete an NPC, including NPC-based CC such as Beck's Child's Bike and her animated farm animals.
But I'm wondering exactly how to apply this rule. For instance, does it apply only to the neighborhood where it was purchased and put into the game? Or does it affect all neighborhoods regardless of using it?

Here is why I ask . . .
I reinstalled Windows 7, which meant a new installation of Sims. I added my downloads folder (with several of Beck's items) but did not open any of the neighborhoods. When I got to that screen I was satisfied the install went well and I quit the game in order to get everything else in order.

Now, I'd like to remove most/all of those NPC CC items from THIS downloads folder.
But . . .
I'd like to have a separate downloads folder, for an historical game, and would like to include the many of Beck's animated items.

Is this doable? Can I switch out the downloads folder and run one game with the NPC and another without?
If that is possible, is there anything else I need to be aware of -- aside from not opening the regular game with the historical downloads folder in place? For instance, do I need to remove my regular neighborhood folders and put the historical neighborhood in by itself?

Once in the downloads folder any and all hood that you have played have them in it even though you never bought them.

Just make sure never to open a hood while the historical game downloads are in.

That is the safest way to do it, take out all hoods and there downloads folder and place in the historical game hood and downloads and you should be good to go.

Thanks. That helps a great deal.

You can also put the package files actually containing the NPCs into your historical 'hood's Characters folder, instead of the Downloads folder; that way they won't get into your other 'hoods if you accidentally open another 'hood with your historical CC installed, although it will mean the affected historical CC will only work properly in your historical 'hood.

Thanks, Nysha. I had no idea I could do that.
Having it available only to that particular historical hood would be ideal. Less chance of messing things up if I forget to properly swap something out.

The easiest and safest way to do it is to make a separate game for the historical neighborhood. Rename the old "The Sims 2" folder (or temporarily move it out), let the game recreate a new folder, and use this for the historical game. You can have a separate Downloads folder and everything, and you can switch between the games by renaming the folder. The game will run whatever folder is named "The Sims 2". The games will never mix, and the 'hoods and Downloads folders will always be separate from each other. If you accidentally start up the wrong game, you don't have to be afraid of using the wrong Downloads folder.

You can also copy a game (for instance if you want to test out a mod, or you want two games to go in different directions), and later delete the copy, without any consequences to your other game folders.

I've had up to 4 game folders at the same time, but there's no other limitation other than the space on your computer.

Simmer22, I think you're right about your way being the safest.
In fact, I returned to this thread to leave a link to a post I just found with instructions on how to create two Sims 2 folders (for those of us who didn't know how) that can be renamed to change the one in play.
http://www.modthesims.info/showthread.php?t=595985

Doing this will be the easiest alternative to not using AnyGameStarter (also mentioned in that thread). I have Double Deluxe and all the EPs on disc, but I think it doesn't work because my EPs are compilations (Best of Business instead of Open for Business, Fun with Pets instead of Pets, etc.)