Here is a custom action that will add the appropriate registry entries to replace a locked file on system restart.

To use this action, you would add the new file that will replace the currently locked file somewhere in your application directory.  Then configure the action by defining the path from the application directory to the locked file that will be replaced, as well as the new file that was added during the update.  This action currently requires the file to be within the application directory, but the source code is provided so you can modify this behavior if you wish.

What this action does is explained in the following Microsoft KB article.

http://support.microsoft.com/kb/181345

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ReplaceFileOnRestartAction.zip (49kb) downloaded 27 time(s).

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