I'd like to share my personal batch file. It works on Windows 7, at least:
@echo off
del "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\CASPartCache.package"
echo CASPartCache deleted
del "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\scriptCache.package"
echo ScriptCache deleted
del "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\compositorCache.package"
echo compositorCache deleted
del "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\simCompositorCache.package"
echo simCompositorCache deleted
del "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\socialCache.package"
echo socialCache deleted
del "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\Thumbnails"
echo thumbnails cleared
del "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\WorldCaches"
echo world cache cleaned
attrib +r "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\DCBackup\ccmerged.package"
echo ccmerged made readonly
del "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\DCBackup"
echo DCBackup cleaned
attrib -r "%USERPROFILE%\Documents\Electronic Arts\The Sims 3\DCBackup\ccmerged.package"
echo ccmerged made readwrite
start /d "C:\Program Files\Electronic Arts\The Sims 3 Seasons\Game\Bin" Sims3Launcher.exe
echo game launching
pause
exit
Basically it deletes every file possible (cache files, DCBackup, Thumbnails and World Caches) and then tells me that it deleted them. It then launches the game, tells me it did that, waits for confirmation, then exits. Best thing is, I don't even need to bother changing Usernames - %USERPROFILE% means your User Profile - so for instance, if my username was "Seabody", it'd mean C:\Users\Seabody - if it was "Orangutan", it'd mean C:\Users\Orangutan.