What would you suggest I use to update some outdated files on users computers? Some of the files I need to update are dll files (system32) and some datafiles (program directory). Some of the dll files are registered dll's (with regsvr32) and others not.

The program were packaged with PDW but if I use it again to update the outdated files I get a second instance of the program in Installed Programs under Control Panel.

If I write my own update program; Would I need to unregister the registered DLL's, copy the newer file and re-register the DLL's or can I just copy the newer file into the system32 directory? If I need to re-register the DLL's, can it be done programmatically and how?