I am in the process of making a backup of all my CC , lots and sims because I want to reinstall my PC. But I am not sure where I can find the sims that I saved in CAS. So, I am talking about the premade sims in CAS that you can use as template for a new sim. Is this possible? And if so, where is the location of the files?

They should be in your saved sims folder.

Have fun! I spent over 20 hours cleaning up my backups from my backups. I practically gave myself carpal tunnel, but all the stuff is organized now. I didn't keep track of how much I got rid of. I stopped counting after 10 gigs...

Now that I know where the files are, I realise that I didn't save all my favourite sims' looks and lots That will take a while I guess.

Also, because I am going to run linux. I know that the Sims 3 will run, but I was wondering if anyone managed to use the sims 3 tools under linux. Like RegulsaveCleaner?

Lots will be saved to library. Finding them can be a PITA if you have many, as they will have generic numbering and if you do not know approximate date saved, must open them one at a time in S3PE and look at the icon to see what it is. Also, If you made a Sim, and then added her to your world via town edit, she will also be in library, and similar PITA of looking at snaps. If you saved Sims or lots from edit town, they are also in library.

Only CAS Sims that you click 3 dots near thumbnail and then save to bin are in the saved Sims bin.

I was going to backup the library and then in the newly installed game, delete the sims that were saved there. As for the sims, I am only interested in the ones saved in CAS so they can be used as template for new sims. But thanks for the warning

If you wish to delete Sims from libbrary, you can do that in edit town.

Yes, that is what I meant. The sims in edit town will be deleted after putting back the library backup. I just want to keep the lots in library and the sim templates in CAS.