Chaining Hotfix Installations Without QChain.exe Is not safe!!!
When you install hotfixes, if a file is locked or in use and cannot be replaced, it is placed in the Pending File Rename queue to be replaced after the restarts. The problem occurs in this scenario: You install hotfixes A and B without rebooting between installations.
Both packages contain file X. Package A's file X is version of 3; package B's fix X is version 2. The version of file X on the computer is version 1.
When package A is installed, it places its version of file X in the Pending File Rename queue.
When package B is installed, it places its version of file X in the Pending File Rename queue.
When the computer is rebooted, because package B was installed last, its version of file X is installed (in the Pending File Rename queue, the last file is the one that is used). You end up with version 2 instead of version 3 as you expected.
Microsoft Support Articles Q296/8/61
When you install hotfixes, if a file is locked or in use and cannot be replaced, it is placed in the Pending File Rename queue to be replaced after the restarts. The problem occurs in this scenario: You install hotfixes A and B without rebooting between installations.
Both packages contain file X. Package A's file X is version of 3; package B's fix X is version 2. The version of file X on the computer is version 1.
When package A is installed, it places its version of file X in the Pending File Rename queue.
When package B is installed, it places its version of file X in the Pending File Rename queue.
When the computer is rebooted, because package B was installed last, its version of file X is installed (in the Pending File Rename queue, the last file is the one that is used). You end up with version 2 instead of version 3 as you expected.
Microsoft Support Articles Q296/8/61
