Clean up folders/files & RunOnce or RunOnceEx

Hi, when I'm creating an application bundle it's frequent that I need to delete files and/or folders at the end of the installation. Under Windows XP I normally just add a RunOnce or RunOnceEx registry key that call a batch file on next reboot and the job is done. Now on Windows 7 it doesn't work the same way. I end up having many computers that do have my RunOnce keys created but they never get launch. I found this on the subject: Standard user: RunOnce and RunOnceEx are not being executed. So I would be very interested in learning how others do it?! How do you clean up after the installation? Sometimes the OS has a lock on some installation files and you just can't delete them right away.

Thanks in advance for the help!