Do Microsoft Windows OS file versions contain ALL earlier hotfixes?
I don't know if this answers your specific question...but I liked the question enough to research it out and found this:
http://blogs.msdn.com/b/ntdebugging/archive/2008/10/21/windows-hotfixes-and-updates-how-do-they-work.aspx
Specifically (in case the link goes dead):
Installing a Hotfix
By default, all components on Windows systems start on the GDR branch following each major release. When you install updates from Windows Update for a GDR component, it gets upgraded with the GDR version.
When you install a specific Hotfix, the files and components in the Hotfix package are migrated to the LDR branch. At this point, that particular component is marked as a LDR component. If you install a newer Update over this component, the Windows servicing technology will automatically install the appropriate latest version from the LDR branch for you. This is possible because each Update package ships with both the GDR and LDR versions of the component.
Once a component is marked as a LDR component, the only way to move back to the GDR branch is to uninstall all Hotfixes for that component, or move to the next available service pack.
What would happen if a user installed a Hotfix, and then sometime later installed the next service pack? Well, in that case it depends on the Hotfix and when it was built.
If the Hotfix was built before the service pack, then the component will be moved to the GDR version contained in the service pack.
If the Hotfix was built after the service pack, the component will be migrated to the post-service pack version of the component, and will stay on the same branch that it was originally on.
In order to make this work, these packages contain both the RTM GDR version, the RTM Hotfix branch, and the SP1 Hotfix and GDR version of each binary.
All fixes built for Windows are cumulative in nature by branch, i.e. a new update will contain the new fix, as well as all the previous fixes for that branch. Referencing the chart above, installing fix #4 can get you fixes #2 and #4 on the GDR branch. If the component is on the LDR branch, then the user would get fixes #1-4.
Finally, the servicing technology has to handle the case where you need the functionality of an older Hotfix (e.g. “Fix #1” in the diagram above) but you may already have installed “Fix #4” which might be a critical security update. What happens is that when the GDR branch of a fix is installed, it also places a copy of the Hotfix version of the same fix on the system. When you run the installer for Hotfix #1, it detects that a newer version of the file is already installed, but it also detects that it needs to migrate it to the Hotfix version of the binary that was previously stored on the system. The result is that you end up with the Hotfix binary for Fix #4, which has both the Hotfix you need plus the cumulative set of security fixes.
Hope that helps you.