You do not need SimPe to do that, it is quite simple but you need to do this first.
Make a safe copy of your Downloads, savedsims (if you create your own sims template in bodyshop so they won't be lost), lotcatalog folder (if you have cc houses you are using as template in your house bin) and any other folder you know you have cc stuff in, they are all located in your C:/mydocuments/eagames/thesims2 folder.
Once this is done, delete the sims 2 folder. When you will start the game, it will recreate all the folder exactly like they were at the begining. Know that you will loose all your cc hood though if you do this and you will have to redo all your game settings. If you do not want to loose your cc hood, make a copy of any that are in the C:/mydocuments/eagames/thesims2/neighborhoods folder that are higher than N003. G001 is Riverblossom, N001 is Pleasantview, N002 is Strangetown, N003 is Veronaville, N004 and higher are your cc hood.
Once the game recreated them, quit it and you can put back your folders in place if you wish to keep your cc stuff. Do not forget to re-enable cc in the main window when you start the game.
Have fun, it can be nice to start from scratch.
