>How can you install updates to the shared DLLs? Whenever I try, I get "MFC42.DLL in use - retry?" errors from the setup program.

What setup program are you using? Are you refering to a setup that you created, or are you trying to install a program? Most installation programs detect when a file is in use, then will prompt you to reboot the machine, which will replace the old dll with the new dll that the setup program wants to install.

Best,

jody