When updating or uninstalled a Windows Installer application you may get a "File in use" dialog due to a file in use. The locked file that is triggering the "File in use" dialog might not belong to the application being uninstalled. The commonality may only be that the locked file shares the same name as a file being uninstalled.
The cause of the problem is a code defect.
There is no hot fix available. It is recommended that the Restart Manager be used whenever possible. The Restart Manager is available in client operating systems Vista and later, and Servers 2008 and later. It is enabled by default.